Let me preface this answer by saying that due to my experience in 2016 contrasted with my 2015 experience, I personally think soil conditions and composition, kinds of light and light levels, and how you water your tomatoes may have a profound affect on heat-tolerance.
Since the temperature in your area fluctuates so much between day and night, the rules are a little bit different. I know the daytime highs in your area might get well into the hundreds, even for extended periods, but it's also important to know that the lows can sometimes be so low that it's actually too cold for many tomatoes to set fruit. For instance, if the temperature drops 35 degrees at night and the daytime high was 89° F., then the low would be 54° F., which may be too cold for many tomatoes (ideal night-time temperatures are supposed to be between 59 to 68° F. or so). Therefore, it stands to reason that not only will heat-tolerant tomatoes be more productive, but that cold-tolerant ones will be, too.
Some tomatoes are said to have both heat and cold tolerance. Here are some varieties:
Heat and cold tolerant tomatoes
However, it's important to note that your area is dry. Some tomatoes do better in wet heat than dry heat, and vice versa.
In my own personal experience, the following tomato varieties produce well in the conditions you described:
- Black plum (sets fruit in both sun and partial shade)
- Early Girl
- Galapagos Island (Solanum cheesmaniae)
- Husky Cherry Red F1
- Lemon Boy F1
- Pruden's Purple
- Red Pear
- Roma
- Yellow Pear
Partially heat-tolerant (in my own experience):
- Market Wonder (mostly not heat-tolerant, but I got at least one tomato in the heat, and the plants grew very well in heat, drought and poor soil conditions; my seeds came free from wintersown.org)
- Sugar Lump (got two tomatoes in the heat; plants much prefer cooler conditions; the plants did not grow well in heat, drought and poor soil conditions; my seeds probably came from a dollar store.)
- Texas Wild Cherry (The plant grew fine in heat, drought, and poor soil conditions, but I wasn't as impressed as I was led to believe I would be. It didn't set fruit in as hot of conditions as most heat-tolerant tomatoes, but it did set fruit in hotter conditions than regular tomatoes. My seeds came free from wintersown.org)
It should be noted that people sometimes just get around the problem of summer heat by growing early tomatoes that start producing fruit before it gets very hot.
Another tip is to save your own seeds every year to plant the next. I read that if you get the plants used to your climate for generations, it's supposed to help improve yields and things. I'm trying it. We'll see how it goes. Ask me about it in several years.
I've also read that grafting can help with the heat tolerance. I assume this means that if you graft a tomato that isn't heat tolerant onto a heat tolerant one, perhaps the result may be more heat tolerant. If you try it, let us know if it works.
Also, look for all-weather tomatoes, and those that are said to produce all season.
Okay, so I compiled a list of tomatoes that people have claimed have heat tolerance. The level of heat tolerance isn't specified. So, take this with a grain of salt, and do your own investigation on varieties that perk your interest. My sources include such as customer reviews on varieties at online vendors (such as rareseeds.com) or reviews at gardening websites (such as davesgarden.com), cuke.hort.ncsu.edu, and tomatoes I found via random sites on a search engine, as well as a few varieties I know from personal experience. If a tomato is under one category, that does not necessarily mean it doesn't belong in the other category, too. It's possible that some tomatoes on the list that aren't labeled as hybrids actually are hybrids, too, but most of them should be the sort to breed true. This list is not exhaustive, and I do plan to add to it, in future.
Heat-tolerant tomatoes:
- Abu Rawan
- Al-Kuffa
- APT 403
- Argentina Cherry
- Arkansas Marvel
- Arkansas Traveler
- Aussie
- Bali
- Basrawya
- Beefsteak (not all strains are heat-tolerant, but some are said to be)
- Bella Rose (hybrid)
- BHN 189 (hybrid)
- BHN 216
- Big Beef (hybrid)
- Black Cherry
- Black from Tula
- Black Mauri
- Black Plum (also shade tolerant, during heat)
- Black Prince
- Blue Berries
- Bradley
- Brandyboy (hybrid)
- Brandywine OTV (shows more heat-tolerance than regular Brandywine)
- Brenda
- Burbank Slicing
- Burgundy Traveler
- Burnley Gem
- Butte
- Caiman (hybrid)
- Cal Ace
- Carmello
- Celebrity (hybrid)
- Chadwick Cherry or Camp Joy Tomato (sets fruit in 115° F.)
- Champion
- Chef's Choice Pink (hybrid)
- Cherokee Purple (it didn't prosper in dry heat and drought where I live)
- Chico III
- Chocolate Pear
- Ciudad Victoria
- Coldset
- Copia (Tigercopia)
- Costoluto Fiorentino
- Costoluto Genovese
- Cour di Bue (oxheart)
- Creole
- Cuautli Salubong
- Cuostralee (or Coustralee)
- Cyriuss (hybrid)
- Dad's Sunset
- Djodah
- Earl's Faux
- Early Girl (hybrid)
- Equinox (hybrid)
- Eva's Purple Ball
- Fireworks
- Flamenco
- Floradade
- Florasette
- Florida (hybrid)
- Florida 91 (hybrid)
- Florida Pink
- Fourth of July (hybrid)
- Freshmarket 9
- Galapagos Island (Solanum cheesmaniae)
- Genuwine (hybrid)
- German Red Strawberry
- Gezahnte
- Giallo de Summer
- Glacier
- Glamour
- Gold Medal
- Golden Jubilee
- Golden Marglobe
- Grandfather Ashlock
- Great White
- Green Zebra
- Grosse Lisse
- Haley's Purple Comet
- Hawaiian Currant
- Hazelfield Farm
- Heatmaster (hybrid)
- Heatwave II (hybrid)
- Henderson's Pink Ponderosa
- Homestead
- Homestead 24
- Hotset
- Hunter
- Husky Cherry Red (hybrid)
- Hy Brix (hybrid)
- Illinois Beauty
- Kamatis Tagalog
- Kellogg's Breakfast
- Kewalo
- Kimberly
- Ladybug (hybrid)
- Lollipop
- Louisiana All Season
- Lucid Gem
- Manalucie
- Marianna's Peace
- Marion F
- Marizol Korney
- Marmande (Beefsteak)
- Martino's Roma
- Marvel Striped
- McMurray # 10
- Mely (hybrid)
- Mexican
- Mexico Midget Cherry
- Mighty Red (hybrid)
- Momotaro
- Moneymaker
- Mortgage Lifter
- Mountain Crest (hybrid)
- Mountain Glory (hybrid)
- Mountain Princess
- Mozark
- Mule Team
- Neptune
- Nichols
- Nineveh
- Notchli
- Omar's Lebanese
- Orange Banana
- Ozark Pink
- Penny's Early
- Penny's Golden Cherry
- Persimmon
- Phoenix
- PickRipe (hybrid)
- Pik Rite (hybrid)
- Pineapple (tolerates heat, cold and drought)
- Pink Beauty (hybrid)
- Pink Bumblebee
- Pink Siberian Tiger (grows well in cool or hot climates according to mariannasheirloomseeds.com)
- Ponderosa Gold
- Pork chop
- Porter
- Porter's Dark Cherry (hybrid)
- Principe Borghese
- Prize of the Trials
- Processor 40
- Processor 278
- Pruden's Purple
- Punta Banda
- Purple Bumblebee
- Purple Calabash
- Quarter Century
- Red Global
- Red Pear
- Red Star
- Red Star Cherry
- Reno
- Road Runner (hybrid)
- Roma
- Rouge D' Irak
- San Marzano
- Sanibel (hybrid)
- Serrat (hybrid)
- Sioux
- Skyway 687 (hybrid)
- Solar Fire (hybrid)
- Solar Set (hybrid)
- Southern Nights
- Spitfire (hybrid)
- State Fair
- Stupice (hot and cold weather)
- Summer Set (hybrid)
- Sun Chaser
- Sun Gold (hybrid)
- Sun Leaper
- Sun Pride
- Sun Sugar (hybrid)
- Sunbeam (hybrid)
- Sunmaster
- Super Fantastic (hybrid)
- Super Sioux
- Supremo (hybrid)
- Sweet Orange Cherry
- Syrian Giant*
- Talladega
- Taos
- Texas Wild Cherry
- Tlacolula (AKA Tlacolula Ribbed)
- Tommy Toe
- Top Gun (hyrbid)
- Toro (hybrid)
- Traveler 76
- Tribute
- Tropic (hybrid)
- Tycoon
- Valencia
- Viva Italia (hybrid)
- Wayahead
- White Tomesol
- Wild Florida Everglades (Solanum pimpinellifolium)
- Yellow Pear
- Yellow Ruffled
Handles dry heat:
- Black from Tula
- Black Plum
- Black Prince
- Burnley Gem
- Chadwick Cherry or Camp Joy Tomato (sets fruit in 115° F.)
- Chocolate Pear
- Copia (Tigercopia)
- Earl's Faux
- Early Girl (hybrid)
- Flamenco
- Galapagos Island (Solanum cheesmaniae)
- Glamour
- Gold Medal
- Husky Cherry Red (hybrid)
- Mexican
- Nichols
- Notchli
- Penny's Early
- Porter's Dark Cherry (hybrid)
- Punta Banda
- Red Pear
- Roma
- Super Sioux
- Yellow Pear
Handles wet heat:
- Abu Rawan
- Arkansas Marvel
- Arkansas Traveler
- Champion
- Cherokee Purple (doesn't handle dry heat well where I live)
- Cour di Bue (oxheart)
- Cuostralee (or Coustralee)
- Creole
- Dad's Sunset
- Floradade
- Glacier
- Homestead 24
- Kewalo
- Louisiana All Season
- Manalucie
- Moneymaker
- Mortgage Lifter
- Nineveh
- Penny's Early
- Ponderosa Gold
- Purple Calabash
- Solar Fire (hybrid)
- Tommy Toe
- White Tomesol
- Wild Florida Everglades
Tomatoes with disputed heat tolerance
(These tomatoes have been reported to be heat-tolerant, but this claim is disputed.)
- Beefsteak: Peaceful Valley's and American Seed's Beefsteak were not heat-tolerant for me. Other people have reported Beefsteak (from unknown vendor/s) to be heat-tolerant, however.
- Black Sea Man: This site says it's not heat-tolerant.
- Brandywine: Flowers didn't set fruit until it cooled, in my area. (This needs more testing, since there's a chance that what I grew wasn't Brandywine.)
- Cherokee Purple (potentially disputed; need to test more)
- Kellogg's Breakfast: This needs to be tested more to be sure, but from my observations of growing it, I didn't detect particular heat-tolerance.
- Martino's Roma: It's about as heat tolerant (to dry heat) as Paul Robeson is (maybe a little less), in my experience
- Paul Robeson: It probably has above-average heat tolerance in dry heat, but in my area the flowers didn't set viable fruit until it cooled down somewhat, whereas varieties like Black Plum and Pruden's Purple set quite a while beforehand. However, it did set a lot of fruit when it cooled down (but my plant was grown indoors to a good age before being planted outdoors in the spring). This variety is definitely drought tolerant in containers indoors, however.
- Pomodoro San Marzano
- Texas Wild Cherry (potentially disputed, but seems to do well in Texas, from reports)
- Wild Florida Everglades
Tomatoes that probably have heat tolerance:
- Basketvee: Coldset, which is heat-tolerant, is in its parentage: (Campbell 1402 x Coldset) x (Coldset x Heinz 1350)
- Big Sungold Select [Selection from Sungold.]
- Chef's Choice Orange: one parent is Amana Orange, which is heat-tolerant (and the seemingly related Chef's Choice Pink is heat-tolerant).
- Cherokee Green
- Cherokee Lime
- Green Pear
- Green Tiger (reported to be prolific in Atlanta, Georgia)
- Grub's Mystery Green
- Heidi
- Mac Pink: Coldset and Homestead are heat-tolerant and are in its parentage: (unnamed pink selection x Homestead) x Coldset
- Malakhitovaya Shkatulka
- Mama Mia
- McGee (was grown extensively throughout Texas and the southern states for many years, but I suppose it may have been grown for its early qualities rather than its ability to set fruit in heat)
- Orange Cherry [Selection from Sungold.]
- Oroma: part Roma and Santiam (Roma can be heat tolerant)
- Payette—This tomato was bred in Parma, Idaho, which is within about an hour of the Oregon High Desert; its parentage includes these (at least one of which is heat-tolerant, and at least one is cold-tolerant): L. peruvianum, L. hirsutum, Bison, Stokesdale, Sioux, Bounty
- Saucy: part Roma and Santiam (Roma can be heat-tolerant)
- Sweet Ozark Orange (said to produce better than Big Beef in Hutto, Texas; one of its parents is also heat-tolerant)
- Veebrite: Parentage: [(C1402 x Coldset) x (Coldset x Heinz 1350)1
- Vision: Parentage: Campbell 1327-D19 x Coldset
Some varieties are parthenocarpic. This means they don't need pollen to produce fruit. Those might, in theory, do well whether it's hot or cold. It's well established that they can do well in the cold, but some people say they don't necessarily do well in the heat. Here are some:
Parthenocarpic varieties:
(Note: Not all have the same degree or kind of parthenocarpy)
- Carebeta
- Early North
- Farthest North might be parthenocarpic
- Golden Nugget (probably the same thing as Gold Nugget)
- IVT-1
- IVT-2
- Kyo-akane
- Kyo-temari
- Legend
- Line 75/79
- Lycopea
- Montfavet 191 (highly female sterile)
- Oregon 11
- Oregon Cherry
- Oregon Pride
- Oregon Spring (it should be noted that Siletz is considered an improvement on this)
- Oregon Star
- Oregon T5-4
- Oroma
- P-26
- P-31
- Parteno
- PI-190256
- Pobeda
- PSET 1
- Rarkuna First
- Renaissance
- RP 75/59
- Santiam
- Saucey
- Saucy (probably the same thing as Saucey)
- Severianin
- Siletz (it should be noted that Legend is considered an improvement on this, although some people prefer Siletz to Legend)
- Stock 2524
- Sub Arctic Plenty
The main parthenocarpic varieties I would recommend looking into are Oroma, Saucey, Siletz, Golden Nugget, Santiam and Legend.
Note that territorialseed.com and victoryseeds.com sell many of these parthenocarpic tomatoes (territorialseed.com also sells other kinds of parthenocarpic seeds, such as the Planet Pepper, and Cavili summer squash).
Cold-tolerant tomatoes:
- Anna Russian
- Apollo Improved (hybrid)
- Aussie
- Azoychka
- Basketvee
- Beaverlodge Slicer
- Bellstar
- Better Boy (hybrid)
- Big Mama (hybrid)
- Bison
- Black Cherry
- Black from Tula
- Black Prince
- Bloody Butcher
- Bosque Blue
- Brown Sugar
- Bush Beefsteak
- Celebrity (hybrid)
- Coldset
- Cosmonaut Volkov
- Cuautli Salubong
- Djodah
- Dona (hybrid)
- Early Cascade (hybrid)
- Early Girl (hybrid)
- Galina's (AKA Galina)
- Glacier
- Golden Nugget (hybrid)
- Gregori's Altai
- Grushovka
- Husky Gold (hybrid)
- Kimberly
- Kotlas
- Legend
- Lime Green Salad (AKA Green Elf; said to have handled temperatures at least as low as 25° F. by an Illinois reviewer on davesgarden)
- Manitoba
- Marmande
- McGee
- Mira
- New Jersey 300
- New Yorker
- Nodak
- Northern Delight
- Notchli
- Orange Pixie (hybrid)
- Oregon Spring (hybrid)
- Oroma
- Oxheart
- Paul Robeson (This isn't heat tolerant, in my experience so far, though.)
- Persimmon
- Pineapple
- Pink Bumblebee
- Pink Siberian Tiger (grows well in cool or hot climates according to mariannasheirloomseeds.com)
- Pink Vogue
- Polar Baby
- Polar Beauty
- Polar Star
- Prairie Fire
- Principe Borghese
- Pruden's Purple
- Purple Bumblebee
- Quick Pick (hybrid)
- Rouge de Marmande
- Santa
- Santa Cruz Kada
- Sasha's Altai
- Siberia
- Siberian
- Siletz (hybrid)
- Silvery Fir Tree
- Small Wonder
- Stupice
- Sub Arctic
- Sugar Baby
- Sun Gold (hybrid)
- Sun Sugar (hybrid)
- Super Marmande
- Sweet 100 (hybrid)
- Sweet Baby Girl (hybrid)
- Taos
- True Black Brandywine
- Veebrite
- Veecrop
- Vintage Wine
- Vision
- Vivid
- Wheatley's Frost Resistant
- Yellow Pear
Here's a list of early tomatoes, without regard to temperature tolerance (days to maturity, whether determinate/indeterminate and whether a hybrid are listed in parentheses):
- Sub-Arctic Plenty; Sub-Arctic; World's Earliest Tomato (42-59; det)
- Siberian (48-60; det)
- Sub-Arctic Maxi (48-65; det)
- Sweet 'n' Neat Cherry (48-68; compact det; hybrid)
- Sweetie (50; ind)
- Siberia (50; det)
- Early Girl (50-52; ind; hybrid)
- Galapagos Island; Solanum cheesmaniae (50-60; ind)
- Kimberly (52; ind)
- Stupice (52; ind)
- Beaverlodge Slicer (52-54; det)
- Lime Green Salad (52-58; semi-det)
- Siletz (52-75; det)
- Bush Early Girl (54; det; hybrid)
- Bloody Butcher (55; ind)
- Early Cascade (55; ind)
- Galapagos Island; Solanum galapagense (55; ind?)
- Gardener's Delight (55; ind)
- McGee (55; ind)
- Mountain Princess (55; ind)
- Alaska Fancy (55; det)
- Early Wonder (55; det)
- Golden Nugget (55; det)
- Beaverlodge 6808 Slicer (55; compact det)
- Elfin (55-60; det)
- Sun Gold (55-65; ind; hybrid)
- Tess's Land Race Currant (55-68; ind)
- Santiam (55-75; det)
- Oregon Spring (55-80; det)
- Northern Lights (55-90; ind)
- Glacier (56; det)
- Sasha's Altai (57; det)
- Matina (58; ind)
- Salisaw Cafe (58; ind)
- Manitoba (58; det)
- New Girl (58-65; ind; hybrid)
- Clear Pink Early (58-75; det)
- Aurora (59; det)
- Golden Bison (59; det)
- Crazy (60; ind)
- Fireworks (60; ind)
- Green Grape (60; ind; hybrid?)
- Juliet (60; ind; hybrid)
- Juliet Roma Grape (60; ind; hybrid)
- Kotlas (60; ind)
- Moskovich (60; ind)
- Zarnitza (60 ind)
- Moskvich (60; semi-det)
- Viktorina (60; semi det)
- Betulax (60; det)
- Big Dwarf (60; det)
- Clear Pink (60; det)
- Early Annie (60; det)
- Lime Green Salad; Green Elf (60; det)
- Sprite (60; det)
- Sweet 'n' Neat Scarlet (60; compact det; hybrid)
- Washington Cherry (60; det)
- Bush Beefsteak (60-62; det)
- Rosalita (60-65; ind)
- Legend (60-68; det)
- Momotaro (60-78; ind; hybrid)
- Isis Candy (60-80; ind)
- Thessaloniki (60-80; ind)
- Green Giant (60-85; ind)
- Rutgers (60-100; det)
- Koralik (61; det)
- Grape; Timi G (62; ind; hybrid)
- Sweet Pea Currant (62; ind)
- Gold Dust (62; det)
- Alaska (63; semi det)
- New Yorker (63; det)
- Container's Choice (63-70; det; hybrid)
- Tumbling Tom Red (63-70; compact det cascading; hybrid)
- Tumbling Tom Yellow (63-70; compact det cascading; hybrid)
- Sweet Israeli (64; det)
- Black Cherry (65; ind)
- Currant (65; ind)
- Early Orange Stripe (65; ind)
- Matt's Wild Cherry (65; ind)
- Park's Whopper CR Improved (65; ind; hybrid)
- Slava (65; ind)
- Sugar Lump (65; ind)
- Super Sweet 100 (65; ind; hybrid)
- Sweet Baby Girl (65; ind; hybrid)
- Sweet Million (65; ind; hybrid)
- Yellow Marble (65; ind)
- Husky Cherry Red (65; dwarf-ind; hybrid)
- Bosque Blue (65)
- Celebrity (65; det; hybrid)
- Coldset (65; det)
- Grushovka (65; det)
- Minibel (65; det)
- Taxi (65-68; det)
- Anna Russian (65-70; ind)
- Azoychka (65-70; ind)
- Florida 91 (65-70; det; hybrid)
- Amy's Sugar Gem (65-71; ind)
- Heatmaster (65-75; det; hybrid)
- Bison (65-77; dwarf det)
- Goliath (65-85; ind; hybrid)
- Paul Robeson (65-90; ind)
- Optimus (67; semi det)
- June Pink (68; ind)
- Peche Jaune (68; ind)
- Cosmonaut Volkov (68; ind)
- Earlianna (68; ind)
- Marmande (68; ind)
- Peron; Peron Sprayless (68; semi-det)
- Better Bush (68; det; hybrid)
- Bush Goliath (68; det; hybrid)
- Punta Banda (68; det)
- Zhefen Short (68; det)
- Biltmore (68-74; det; hybrid)
- Black Krim (69; ind)
- Early Yellow Stripe (69; ind)
- Mrs. Maxwell's Big Italian (69; ind)
- Nicholas Doochov (69; ind)
- Orange Roma (69; ind)
- Porter's Pride (69; ind)
- Chiapas Wild (69; det)
- Prescott (69; det)
Heat tolerant eggplants:
- Aswad
- Black Bumper
- Black King
- Orient Express (hybrid)
- Pingtung Long
Eggplants that probably have some degree of heat tolerance:
- Bangladeshi Long
- Banka (said to do well even in poor summer conditions; 105 days)
- Florida Market
- Gbogname (plants take heat well, but I don't know if they produce in hot conditions)
- Malaysian Dark Red (plants tolerated the heat, but I don't know if they produced in hot conditions)
- Turkish Orange (Solanum aethiopicum or Solanum integrifolium, depending on who you ask)
- Twilight (hybrid)
Cold-tolerant eggplants:
- Applegreen (70 days)
- Orient Express (hybrid)
Eggplants that are probably cold-tolerant
- Malaysian Dark Red (plants tolerated cold, but I don't know if they produced in colder than normal conditions)
