Fort Thomas, Arizona climate: Normal weather by month, frost dates and records
Fort Thomas's normal year runs from 28°F December nights to 100°F July afternoons, with 10.2 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 18.1°C, December lows of −2°C, July highs of 38°C, 259 mm of precipitation a year.
- NOAA stationFort Thomas (2 mi SW)
- Station IDUSC00023150
- Location33.01°N 109.99°W
- Elevation2,835 ft (864 m)
- Population (census place)319
On October 23, the normal high in Fort Thomas is 82°F and the normal low 44°F, and the chance of measurable rain or snow is 10%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Fort Thomas.
- Jan 61° 28°
- Feb 66° 32°
- Mar 74° 37°
- Apr 82° 44°
- May 91° 53°
- Jun 100° 62°
- Jul 100° 71°
- Aug 98° 69°
- Sep 93° 62°
- Oct 84° 48°
- Nov 71° 35°
- Dec 60° 28°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Fort Thomas each month?
July is the warmest month, with normal highs of 100°F; December the coldest, with normal lows of 28°F. The most precipitation falls in August (1.85 in), the least in June (0.15 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 61°F | 28°F | 44.7°F | 1.01 | 4 | <1 | 23 | 10 h 10 min |
| February | 66°F | 32°F | 48.9°F | 0.98 | 4 | <1 | 15 | 11 h |
| March | 74°F | 37°F | 55.5°F | 0.60 | 3 | <1 | 7 | 12 h |
| April | 82°F | 44°F | 62.9°F | 0.25 | 2 | 4 | 2 | 13 h |
| May | 91°F | 53°F | 71.5°F | 0.37 | 2 | 17 | <1 | 13 h 50 min |
| June | 100°F | 62°F | 81.2°F | 0.15 | 1 | 29 | <1 | 14 h 20 min |
| July | 100°F | 71°F | 85.3°F | 1.74 | 7 | 29 | <1 | 14 h 10 min |
| August | 98°F | 69°F | 83.2°F | 1.85 | 7 | 28 | <1 | 13 h 20 min |
| September | 93°F | 62°F | 77.6°F | 1.10 | 4 | 22 | <1 | 12 h 30 min |
| October | 84°F | 48°F | 65.8°F | 0.73 | 3 | 7 | 1 | 11 h 20 min |
| November | 71°F | 35°F | 53.0°F | 0.50 | 3 | <1 | 11 | 10 h 30 min |
| December | 60°F | 28°F | 44.1°F | 0.92 | 4 | <1 | 23 | 10 h |
| Year (annual) | 82°F | 47°F | 64.5°F | 10.20 | 43 | 136 | 82 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 16°C | −2°C | 7.1°C | 26 mm |
| February | 19°C | 0°C | 9.4°C | 25 mm |
| March | 24°C | 3°C | 13.1°C | 15 mm |
| April | 28°C | 6°C | 17.2°C | 6 mm |
| May | 33°C | 11°C | 21.9°C | 9 mm |
| June | 38°C | 17°C | 27.3°C | 4 mm |
| July | 38°C | 21°C | 29.6°C | 44 mm |
| August | 36°C | 20°C | 28.4°C | 47 mm |
| September | 34°C | 17°C | 25.3°C | 28 mm |
| October | 29°C | 9°C | 18.8°C | 19 mm |
| November | 22°C | 2°C | 11.7°C | 13 mm |
| December | 16°C | −2°C | 6.7°C | 23 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Safford Agricultural Center (22 miles away), gets 0 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00023150; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Fort Thomas?
Normal highs sit between 65°F and 85°F in February, March, April, October and November. Of those, April has the fewest days with rain (2).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00023150.
When is the last frost in Fort Thomas?
In Fort Thomas, the last spring frost (32°F) comes after April 1 in half of years and after April 18 in one year in ten; the first autumn frost comes before November 6 in half of years and before October 21 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- April 11 year in 10 after April 18; 9 in 10 after March 15
- First autumn frost, half of years before
- November 61 year in 10 before October 21; 9 in 10 before November 19
NOAA puts the median frost-free season at 217 days, and the season without a hard freeze (28°F) at 244 days.
A hard freeze (28°F) comes after March 13 in half of springs and before November 16 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Fort Thomas in zone 8b in ZIP code 85535, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Fort Thomas's NOAA station is in zone 8a: the coldest night of a typical year reaches 13°F (17 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in Arizona · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00023150; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get in Fort Thomas?
In a normal year in Fort Thomas, 136 days a year reach 90°F (46 of them 100°F or more), 82 nights fall to 32°F or colder and 43 days bring measurable precipitation.
- Days at 90°F or more
- 136a normal year
- Days at 100°F or more
- 46a normal year
- Nights at 32°F or colder
- 82a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 43a normal year
The highest temperature in this station's record (since 1966) is 116°F, on August 7, 2025; the lowest is 3°F, on January 17, 1987.
The wettest calendar year on that record is 1978, with 16.50 in; the snowiest season is 1987–88, with 4.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00023150; records: ACIS (NOAA Regional Climate Centers), station USC00023150. Records use complete months only; a month missing more than three days is left out.
How sunny is Fort Thomas?
Over a year 85% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Fort Thomas, 5.6 kWh per square metre a day. June is the sunniest month (91%) and July the cloudiest (78%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 83% | 3.4 |
| February | 82% | 4.3 |
| March | 86% | 5.8 |
| April | 89% | 7.2 |
| May | 91% | 8.0 |
| June | 91% | 8.1 |
| July | 78% | 6.5 |
| August | 80% | 6.2 |
| September | 85% | 5.7 |
| October | 89% | 4.9 |
| November | 87% | 3.8 |
| December | 82% | 3.1 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Fort Thomas need?
A normal year in Fort Thomas brings 2,592 heating degree days, 52% fewer than the median U.S. place (5,373), and 2,431 cooling degree days, 2.7 times the median (908). Four months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 5,841 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 629 | 0 |
| February | 449 | 0 |
| March | 298 | 4 |
| April | 112 | 49 |
| May | 20 | 222 |
| June | 0 | 486 |
| July | 0 | 629 |
| August | 0 | 564 |
| September | 1 | 377 |
| October | 70 | 95 |
| November | 364 | 4 |
| December | 648 | 0 |
| Year (annual) | 2,592 | 2,431 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00023150. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
How does Fort Thomas's climate compare?
Fort Thomas is warmer than 47 of the other 96 places with their own NOAA record in Arizona, and wetter than 38. Across the 7,247 U.S. stations with normals, its annual mean of 64.5°F is warmer than 87%.
In the Köppen classification computed from these normals, Fort Thomas is BSh: hot semi-arid steppe. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Fort Thomas share this climate record?
2 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Bylas, AZ1,750 people · 11 mi NW
- Bryce, AZ432 people · 11 mi SE
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Fort Thomas's climate
What is the coldest month in Fort Thomas?
December, with a normal high of 60°F and a normal low of 28°F. The warmest is July (100°F by day, 71°F at night).
Does it snow in Fort Thomas?
Rarely. NOAA publishes no 1991-2020 snowfall normal for Fort Thomas's NOAA station; the nearest record that keeps one, Safford Agricultural Center (22 miles away), records 0 inches of snow in a normal year.
What is the rainiest month in Fort Thomas?
August, with 1.85 in of precipitation in a normal year; the driest is June with 0.15 in.
What plant hardiness zone is Fort Thomas in?
The USDA's 2023 map puts Fort Thomas in zone 8b in ZIP code 85535, the nearest ZIP area. By the same method at Fort Thomas's NOAA station, the coldest night of a typical year reaches 13°F (17 years, 1991-2020): zone 8a.
How late can frost come in Fort Thomas?
In half of years the last 32°F night comes after April 1; in one year in ten it comes after April 18. Waiting until April 18 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Arizona climateThe statewide normals and every place in the state
- Safford Agricultural Center, AZ22 miles from this station, 65.1°F a year
- Safford, AZ23 miles from this station, 66.4°F a year
- San Carlos, AZ34 miles from this station, 64.7°F a year
- Black River Pumps, AZ35 miles from this station, 52.9°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made