Walnut Creek, Arizona climate: Climate normals at a NOAA weather station
Walnut Creek's normal year runs from 21°F December nights to 92°F July afternoons, with 14.8 inches of precipitation and 6 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 12.2°C, December lows of −6°C, July highs of 33°C, 375 mm of precipitation a year.
- NOAA stationWalnut Creek
- Station IDUSC00029158
- Location34.93°N 112.81°W
- Elevation5,090 ft (1,551 m)
On October 23, the normal high in Walnut Creek is 72°F and the normal low 32°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 Walnut Creek.
- Jan 54° 22°
- Feb 58° 24°
- Mar 65° 27°
- Apr 72° 31°
- May 80° 38°
- Jun 89° 44°
- Jul 92° 55°
- Aug 90° 54°
- Sep 85° 46°
- Oct 75° 35°
- Nov 63° 25°
- Dec 53° 21°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like at Walnut Creek each month?
July is the warmest month, with normal highs of 92°F; December the coldest, with normal lows of 21°F. The most precipitation falls in August (2.57 in), the least in June (0.25 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 54°F | 22°F | 37.9°F | 1.51 | 0.3 | 5 | <1 | 28 | 10 h |
| February | 58°F | 24°F | 40.8°F | 1.86 | 1.8 | 6 | <1 | 25 | 10 h 50 min |
| March | 65°F | 27°F | 46.0°F | 1.15 | 1.0 | 5 | <1 | 25 | 11 h 50 min |
| April | 72°F | 31°F | 51.4°F | 0.56 | 0.5 | 3 | <1 | 17 | 13 h |
| May | 80°F | 38°F | 58.5°F | 0.40 | 0.0 | 3 | 3 | 6 | 14 h |
| June | 89°F | 44°F | 66.8°F | 0.25 | 0.0 | 1 | 16 | 1 | 14 h 30 min |
| July | 92°F | 55°F | 73.1°F | 1.84 | 0.0 | 9 | 20 | <1 | 14 h 20 min |
| August | 90°F | 54°F | 71.7°F | 2.57 | 0.0 | 10 | 16 | <1 | 13 h 30 min |
| September | 85°F | 46°F | 65.3°F | 1.50 | 0.0 | 5 | 6 | 1 | 12 h 30 min |
| October | 75°F | 35°F | 54.6°F | 1.00 | 0.0 | 3 | <1 | 11 | 11 h 20 min |
| November | 63°F | 25°F | 43.9°F | 0.89 | 0.3 | 3 | <1 | 26 | 10 h 20 min |
| December | 53°F | 21°F | 36.6°F | 1.23 | 1.6 | 5 | <1 | 29 | 9 h 50 min |
| Year (annual) | 73°F | 35°F | 53.9°F | 14.76 | 5.5 | 56 | 62 | 168 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 12°C | −6°C | 3.3°C | 38 mm | 1 cm |
| February | 14°C | −5°C | 4.9°C | 47 mm | 5 cm |
| March | 18°C | −3°C | 7.8°C | 29 mm | 3 cm |
| April | 22°C | −1°C | 10.8°C | 14 mm | 1 cm |
| May | 26°C | 3°C | 14.7°C | 10 mm | 0 cm |
| June | 32°C | 7°C | 19.3°C | 6 mm | 0 cm |
| July | 33°C | 13°C | 22.8°C | 47 mm | 0 cm |
| August | 32°C | 12°C | 22.1°C | 65 mm | 0 cm |
| September | 29°C | 8°C | 18.5°C | 38 mm | 0 cm |
| October | 24°C | 2°C | 12.6°C | 25 mm | 0 cm |
| November | 17°C | −4°C | 6.6°C | 23 mm | 1 cm |
| December | 11°C | −6°C | 2.6°C | 31 mm | 4 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00029158; 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.
Which months are mildest at Walnut Creek?
Normal highs sit between 65°F and 85°F in March, April, May, September and October. Of those, May has the fewest days with rain (3).
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 USC00029158.
When is the last frost at Walnut Creek?
In Walnut Creek, the last spring frost (32°F) comes after May 24 in half of years and after June 11 in one year in ten; the first autumn frost comes before October 7 in half of years and before September 27 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
- May 241 year in 10 after June 11; 9 in 10 after May 7
- First autumn frost, half of years before
- October 71 year in 10 before September 27; 9 in 10 before October 23
NOAA puts the median frost-free season at 135 days, and the season without a hard freeze (28°F) at 164 days.
A hard freeze (28°F) comes after May 6 in half of springs and before October 18 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Walnut Creek in zone 7b in ZIP code 86305, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, the station is in zone 7b: the coldest night of a typical year reaches 5°F (28 complete years).
Frost dates for every NOAA station in Arizona · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00029158; 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 at Walnut Creek?
In a normal year in Walnut Creek, 62 days a year reach 90°F (5 of them 100°F or more), 168 nights fall to 32°F or colder and 56 days bring measurable precipitation.
- Days at 90°F or more
- 62a normal year
- Days at 100°F or more
- 5a normal year
- Nights at 32°F or colder
- 168a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 56a normal year
- Days with 1 inch of snow or more
- 1a normal year
The highest temperature in this station's record (since 1951) is 114°F, on July 1, 1969; the lowest is −21°F, on December 22, 1968.
The wettest calendar year on that record is 2004, with 26.00 in; the snowiest season is 1918–19, with 59.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00029158; records: ACIS (NOAA Regional Climate Centers), station USC00029158. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Walnut Creek?
Over a year 89% of the sunlight that would reach the ground under clear skies gets through the clouds at Walnut Creek, 5.7 kWh per square metre a day. June is the sunniest month (95%) and December the cloudiest (82%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 84% | 3.3 |
| February | 83% | 4.2 |
| March | 87% | 5.7 |
| April | 90% | 7.1 |
| May | 92% | 8.1 |
| June | 95% | 8.6 |
| July | 86% | 7.2 |
| August | 87% | 6.7 |
| September | 90% | 6.0 |
| October | 91% | 4.9 |
| November | 89% | 3.7 |
| December | 82% | 2.9 |
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 many heating and cooling degree days does Walnut Creek record?
A normal year at Walnut Creek brings 4,663 heating degree days, 13% fewer than the median U.S. place (5,373), and 639 cooling degree days, 30% fewer than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 2,929 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 840 | 0 |
| February | 679 | 0 |
| March | 589 | 0 |
| April | 407 | 0 |
| May | 212 | 13 |
| June | 44 | 98 |
| July | 2 | 253 |
| August | 3 | 211 |
| September | 54 | 64 |
| October | 322 | 1 |
| November | 633 | 0 |
| December | 879 | 0 |
| Year (annual) | 4,663 | 639 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00029158. 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.
Have recent years at Walnut Creek been warmer than normal?
2025 averaged 55.7°F, 1.8°F above the 1991-2020 normal of 53.9°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 55.4°F | +1.5°F | 15.67 | 29.0 |
| 2022 | 55.2°F | +1.3°F | 15.80 | 7.0 |
| 2023 | 53.7°F | −0.2°F | 17.20 | 30.0 |
| 2024 | 55.4°F | +1.5°F | 16.03 | 24.0 |
| 2025 | 55.7°F | +1.8°F | 16.28 | 11.0 |
Over 57 complete years from 1953 to 2025, the station's annual mean temperature rose at a fitted 3.6°F per century (+0.20°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00029158; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Walnut Creek's climate compare?
Walnut Creek is warmer than 16 of the 97 places with their own NOAA record in Arizona, and wetter than 65. Across the 7,247 U.S. stations with normals, its annual mean of 53.9°F is warmer than 57%.
In the Köppen classification computed from these normals, Walnut Creek is BSk: cold 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.
Questions about Walnut Creek's climate
What is the coldest month at Walnut Creek?
December, with a normal high of 53°F and a normal low of 21°F. The warmest is July (92°F by day, 55°F at night).
Does it snow at Walnut Creek?
Yes: 6 inches in a normal year, falling on 1 days with 0.1 inch or more, the most in February (1.8 inches).
What is the rainiest month at Walnut Creek?
August, with 2.57 in of precipitation in a normal year; the driest is June with 0.25 in.
What plant hardiness zone is Walnut Creek in?
The USDA's 2023 map puts Walnut Creek in zone 7b in ZIP code 86305, the nearest ZIP area. By the same method at the station, the coldest night of a typical year reaches 5°F (28 years, 1991-2020): zone 7b.
How late can frost come at Walnut Creek?
In half of years the last 32°F night comes after May 24; in one year in ten it comes after June 11. Waiting until June 11 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Arizona climateThe statewide normals and every place in the state
- Chino Valley, AZ23 miles from this station, 57.0°F a year
- Seligman, AZ28 miles from this station, 55.4°F a year
- Prescott, AZ29 miles from this station, 56.7°F a year
- Bagdad, AZ31 miles from this station, 60.4°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made