Average Monthly Temperature by ZIP Code Map

Average monthly temperature shows the shape of your whole year in 12 numbers. It tells you how cold winter runs, how fast spring warms, how long summer heat lasts, and when fall cools down — the pattern that decides which fruit trees thrive where you live. This map gives you the average monthly temperature for your ZIP code so you can choose plants and plan the season around your own climate.

How to use the map: enter your ZIP code in the search box below or click a spot on the map. A 12-month chart shows the average daily temperature for each month, with each month’s value printed on the chart and the warmest and coldest months in bold. Hover over or tap a month for the exact value; the 32°F reference line shows which months average below freezing.

Each monthly value is the average daily temperature — the mean of each day’s high and low — for that calendar month over 1991–2020, calculated by Food Forest Nursery from gridMET (lower 48 states) and Daymet V4 R1 (Alaska and Hawaii) on a grid of about 4 km (2.5 miles). These are 30-year averages, not today’s conditions or a forecast. Your own yard can run warmer or cooler than its grid cell: cold air settles into valley floors and low spots, while a south- or west-facing wall warms a planting site earlier in spring.

Monthly temperature ties the other climate maps together. Pair it with your chill hours, USDA hardiness zone, AHS heat zone, and growing degree days, and compare it with the soil temperature map to see how far the ground lags behind the air. Browse the rest on our climate maps page.

What Is Average Monthly Temperature?

Average monthly temperature is the typical daily mean for a calendar month: each day’s high and low averaged together, then averaged across that month over 30 years. A July value of 80°F does not mean July afternoons reach 80°F; it might come from highs near 92°F and lows near 68°F. The average marks the middle of the day-night swing, which makes it a good measure of overall warmth and a poor measure of extremes.

How Monthly Averages Help You Choose Fruit Trees

Read your chart as three questions: is winter cold enough, does spring warm at a safe pace, and is summer long and warm enough to ripen fruit?

• Winter chill. Peaches and many other temperate fruit trees need a set amount of winter cold to break dormancy and bloom normally. Utah State, UF/IFAS, and UGA Extension count chill hours as hours between 32°F and 45°F; the original Weinberger model counts every hour below 45°F. Under the 32–45°F model, hours below freezing add nothing, so in cold-winter regions much of the chill comes in late fall and early spring, when temperatures hover above freezing. Your chill hours map gives the actual total.
• Spring warm-up. A warm spell in late winter can wake trees too early. Utah State Extension warns that low-chill cultivars are more prone to break bud during unseasonably warm weather in January or February, and UGA Extension notes that low-chill peaches grown where winters run colder bloom very early and can lose the crop to freezes. Where late frosts are common, choose varieties matched to your chill rather than lower-chill ones, and check your last frost date.
• Summer heat. Growing degree days add up each day’s mean temperature above a base, commonly 50°F (Penn State and Iowa State Extension). A month averaging 70°F delivers about 20 degree days a day, roughly 600 for the month; a month averaging 55°F adds roughly 150. The months on your chart that average above 50°F give a rough sense of how long the season’s heat lasts, and the growing degree days map gives the full total.

Average Temperature vs Hardiness Zone, Heat Zone, and Chill Hours

Average temperature describes the typical month. The other climate maps each measure one threshold or extreme that a monthly average can’t show.

• USDA hardiness zone: based on the average annual extreme minimum winter temperature — the coldest night of the year, averaged over 1991–2020 — in 10°F zones and 5°F half-zones. It tells you whether a plant survives winter.
• AHS heat zone: the average number of days per year above 86°F, the point where the American Horticultural Society says plants begin to suffer heat damage. It tells you whether a plant tolerates your summer.
• Chill hours: winter hours between 32°F and 45°F. They tell you whether winter is cold enough for normal bloom.
• Growing degree days: accumulated warmth above a base temperature. They tell you how much heat the season delivers to grow and ripen a crop.

Two places can share an average temperature and still suit different trees. A mild coastal site and an inland site with hot summers and cold winters can have the same annual average, which is why the 12-month chart tells you more than the single annual number on the map image below.

Why an Average Month Hides Extremes

A monthly average smooths over the cold nights and hot afternoons that do the damage. A January that averages 30°F might come from 40°F afternoons and 20°F nights, and the coldest night of that winter, the measure behind your hardiness zone, falls well below that average low. Summer works the same way: a July that averages 78°F can still bring a string of afternoons in the 90s. Use the averages to judge the shape of your year, and the hardiness, heat-zone, and frost-date maps to judge the extremes your plants have to survive.

Using Monthly Temperatures to Plan the Season

1. Plant while trees are dormant. Bare-root trees go in during the cool months. Check the soil temperature map as well, since South Dakota State Extension times spring bare-root planting for soil of at least 45°F, before buds begin to expand.
2. Track the warm-up. Once monthly averages pass 50°F, degree days on the common 50°F base start to pile up, and bloom and many insect pests follow accumulated heat rather than the calendar.
3. Plan for the hottest stretch. Your bold high month marks the peak of summer. Compare it with your monthly rainfall chart to see whether heat and dry weather overlap, the stretch when new plantings depend most on your watering.

How Accurate Is an Average Temperature Map?

It is a strong 30-year baseline at about 4 km resolution, but it averages the terrain inside each grid cell and cannot see your frost pocket, south wall, or paved driveway. Any single month can run several degrees warmer or colder than normal, and 1991–2020 is a past baseline, not a forecast. Use the chart to compare places and plan; use a local weather station or your own thermometer for day-to-day decisions.

Sources and Further Reading

• Food Forest Nursery’s own calculation of average daily temperature (the mean of each day’s high and low) for each calendar month, 1991–2020 — the base data behind this map. Lower 48 states: gridMET; Alaska and Hawaii: Daymet V4 R1; both on a grid of about 4 km (2.5 miles). The annual map is the mean of the 12 monthly values.
• USDA Agricultural Research Service: USDA Plant Hardiness Zone Map — average annual extreme minimum temperature, 1991–2020, in 10°F zones and 5°F half-zones.
• Iowa State University Extension and Outreach, Linn County: What’s My Zone? — USDA hardiness zones and AHS heat zones.
• UF/IFAS Extension Duval County: Know Your Heat Zone
• Utah State University Extension: How to Grow Peaches in Your Garden
• UF/IFAS Gardening Solutions: Peaches
• UGA Extension: Home Garden Peaches (Circular 1063)
• UGA Extension Peach Blog: Chill Update — the Weinberger and modified Weinberger chill models.
• Penn State Extension: Understanding Growing Degree Days
• Iowa State University Extension and Outreach: Using Growing Degree Days to Manage the Home Garden
• South Dakota State University Extension: Planting Bare-Root Trees

Next step: turn your monthly temperatures into a plant list. Check your chill hours, hardiness zone, and heat zone, read our growing guides for the trees you’re considering, then browse the shop for varieties that fit.