Walnut Creek, AZ Climate: Temperature & Rain by Month
Temperature and precipitation from NOAA NCEI 1991–2020 normals →, plus PlainClimate's derived comfort score
30-year climate normals (1991-2020) from Walnut Creek's primary NOAA station, WALNUT CREEK.
The climate verdict for Walnut Creek
Dryness leads the climate profile for Walnut Creek, Arizona, with 14.8 inches of precipitation a year. NOAA records an annual average of 54°F. At 54/100 (moderate) the climate comfort score falls in the bottom third of the station-mapped U.S. score corpus, exceeding only 31% of scores.
- 54°F
- annual average temperature (NOAA normal)
- 54/100
- comfort score, above 31% of station-mapped location scores
- 14.8"
- annual precipitation · 6" snow
- 136 days
- frost-free days per growing season
Walnut Creek: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00029158 · Walnut Creek, AZ 54°F mean · 14.8" precip
TEMP-COOL · RANK-MID · PHOTO-FINISH · PRCP-DRY · SWING-MID · COMF-LOW · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-COOL 54°F
- RANK-MID #3,911
- PHOTO-FINISH ≈ Reserve Ranger…
- PRCP-DRY 14.8"
- SWING-MID 37°F
- COMF-LOW 54/100
- LOAD-HEAT 4,663 HDD
- STN-1 USC00029158
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Reserve Ranger Station, NM ( -0.2 °F mean)
Instrument codes from this station's NOAA 1991–2020 normals, mean temperature, corpus warmth rank, photo-finish peer station, precipitation band, seasonal swing, comfort composite, degree-day load, and field book, not a livability rating.
Mean-temperature neighbourhood
Nationwide NOAA normal poles and nearest peers, not a reprint of every AZ station list.
- Walnut Creek (this station) 54°F
- Cold Lost Creek Dam, OR 54°F
- Hot Burnsville Ag, NC 54°F
- Near Reserve Ranger…, NM 54°F
- Near Gran Quivira Na…, NM 54°F
Climate Living Index · Walnut Creek
Walnut Creek: 31/100 · grade F
Walnut Creek publishes 5 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 1 missing weight rescale to 100.
PlainClimate-derived for Walnut Creek, not an official NOAA rating. Rankings still use Comfort Score 54/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Snowfall burden | 5.5 inches/year | 70/100 · B |
| Annual temperature balance | 53.9°F · 13.6° from 67.5°F | 56/100 · C |
| Precipitation balance | 14.8 in · 20.2 from 35 in | 27/100 · F |
| Frost-free season | 136 days/year | 16/100 · F |
| Normal heat + freeze calendar | 234 calendar days | 0/100 · F |
Walnut Creek · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Walnut Creek's normals sit in a dry climate class: BSk
Precipitation is low relative to temperature but above true desert thresholds: cold semi-arid steppe (BSk). Class BSk is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: dry (arid or semi-arid), specifically cold semi-arid steppe.
- Köppen code
- BSk
- Group
- Dry (arid or semi-arid)
- Warmest month
- 73.1°F
- Coldest month
- 36.6°F
Source: official public datasets monthly normals (1991–2020) at the city’s primary station. This is a station classification, not a mapped regional consensus.
National standing · heating-led station
Where Walnut Creek sits across the climate record
Three NOAA fields for Walnut Creek's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- 57th percentile warmth
- Mid-pack annual mean versus 6,861 station normals.
- Annual precipitation
- Drier than 83%
- Walnut Creek's annual total ranks in the drier third of 6,352 measured normals.
- Seasonal temperature swing
- Narrower than 78%
- Warmest-to-coldest month gap for Walnut Creek is compact versus 6,861 complete station-years.
How Walnut Creek compares across U.S. station-mapped locations
Walnut Creek's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
54 31st percentile score exceeds 31% of 6,189 station-mapped location scores
- 0–10: 0 station-mapped locations (0%). Below this entry.
- 10–20: 0 station-mapped locations (0%). Below this entry.
- 20–30: 96 station-mapped locations (2%). Below this entry.
- 30–40: 280 station-mapped locations (5%). Below this entry.
- 40–50: 1,113 station-mapped locations (18%). Below this entry.
- 50–60: 1,329 station-mapped locations (21%). This entry sits in this band.
- 60–70: 1,236 station-mapped locations (20%). Above this entry.
- 70–80: 650 station-mapped locations (11%). Above this entry.
- 80–90: 921 station-mapped locations (15%). Above this entry.
- 90–100: 564 station-mapped locations (9%). Above this entry.
Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020
Walnut Creek's measured station temperature trend
MethodologyAcross 57 complete annual observations from 1953 to 2025, WALNUT CREEK warmed at a fitted rate of 0.20°C per decade. The line shows the fitted change relative to its first year, not raw year-to-year temperatures or a forecast.
- Walnut Creek primary station fitted change +0.20 °C/decade
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Snow | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|---|
| January | 54°F (12°C) | 22°F (-6°C) | 38°F (3°C) | 1.5" | 0.3" | 28.2 | 0.0 |
| February | 58°F (14°C) | 24°F (-5°C) | 41°F (5°C) | 1.9" | 1.8" | 24.8 | 0.0 |
| March | 65°F (18°C) | 27°F (-3°C) | 46°F (8°C) | 1.1" | 1.0" | 25.0 | 0.0 |
| April | 72°F (22°C) | 31°F (-1°C) | 51°F (11°C) | 0.6" | 0.5" | 17.2 | 0.2 |
| May | 80°F (26°C) | 38°F (3°C) | 59°F (15°C) | 0.4" | 0.0" | 5.8 | 3.2 |
| June | 89°F (32°C) | 44°F (7°C) | 67°F (19°C) | 0.3" | 0.0" | 0.8 | 15.7 |
| July | 92°F (33°C) | 55°F (13°C) | 73°F (23°C) | 1.8" | 0.0" | 0.0 | 20.2 |
| August | 90°F (32°C) | 54°F (12°C) | 72°F (22°C) | 2.6" | 0.0" | 0.0 | 16.2 |
| September | 85°F (29°C) | 46°F (8°C) | 65°F (19°C) | 1.5" | 0.0" | 0.5 | 5.6 |
| October | 75°F (24°C) | 35°F (2°C) | 55°F (13°C) | 1.0" | 0.0" | 11.0 | 0.4 |
| November | 63°F (17°C) | 25°F (-4°C) | 44°F (7°C) | 0.9" | 0.3" | 25.7 | 0.0 |
| December | 53°F (11°C) | 21°F (-6°C) | 37°F (3°C) | 1.2" | 1.6" | 28.8 | 0.0 |
The year, day by day
Walnut Creek works both ends of the calendar. Normal highs climb to 92°F by July 6 and hold at or above 90°F on 53 dates, then normal lows drop to freezing or below on 181 dates, bottoming at 21°F around December 12.
When the heat sits
Normal highs reach 90°F from June 17 through August 8, covering 53 dates. The broader mild season, normal highs of 70°F or more, runs April 5 to October 29.
This counts calendar dates whose 1991–2020 normal high reaches 90°F. It is a smaller number than the 90°F+ day counts in the monthly table above, which measure how often the threshold was actually crossed in a typical year. A date can average 88°F and still exceed 90°F in half of all years.
The freezing stretch
The normal low stays at or below 32°F into April 21, then returns to freezing around October 24, covering 181 dates in all.
Derived from the normal daily minimum. This is a different measure from the 50%-probability frost dates shown elsewhere on this page, which come from NOAA’s frost product.
Where the wet dates fall
The likeliest wet date is August 5, when 31% of years recorded at least a hundredth of an inch. The driest is June 9 at 6%. Summed across the calendar, that is about 56 wet dates a year.
The widest day
June 11 carries the biggest normal gap between afternoon and dawn, 46°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Walnut Creek.
Where Walnut Creek Stands Nationally
Day-to-night contrast is extreme by national standards — the widest normal daily swing reaches about 46°F, sharper than nine in ten ranked stations see.
Freezing is routine here by normals standards — the normal low reaches 32°F or colder on about 181 nights a year, more than most ranked stations.
Walnut Creek earns 2 nationally notable standings (outer quintiles) against 6,860 NOAA 1991–2020 normals stations; only those extremes render.
Monthly Precipitation
Average monthly rainfall and snowfall
Snow: 0.3"
4.9 days with precipitation
Snow: 1.8"
5.5 days with precipitation
Snow: 1.0"
5.1 days with precipitation
Snow: 0.5"
2.8 days with precipitation
2.6 days with precipitation
1.4 days with precipitation
8.5 days with precipitation
9.5 days with precipitation
5.1 days with precipitation
3.4 days with precipitation
Snow: 0.3"
3.0 days with precipitation
Snow: 1.6"
4.5 days with precipitation
Walnut Creek spreads its precipitation across the year
Neither half of the year dominates here: June through August take 32% of the annual total and December through February 31%, with neither reaching the 35% that would mark a distinct wet season. Walnut Creek has no dry season to plan around, though it does carry a 36.5°F seasonal spread.
The gap between the wettest and driest month still matters: August averages 2.6" and June 0.3". The three wettest months together take 42% of the year, against the 25% a perfectly flat distribution would give them.
Shares are computed from this station's own 1991-2020 monthly precipitation normals. "Spread across the year" means neither the June-August nor the December-February share reaches 35%; it describes an average year, not the variability of any single one.
How Walnut Creek's precipitation splits across the calendar
About 56 days a year record measurable precipitation here, carrying 14.8" between them, or roughly 0.26 inches on a typical wet day. That sits in the middle band: neither the many-light-days pattern of the Pacific Northwest and the Great Lakes, nor the few-heavy-events pattern of the Gulf and the desert Southwest.
A wet day is one recording at least 0.01 inches. These are 1991-2020 normals: they describe an average year and say nothing about the heaviest single storm on record.
Snow reaches Walnut Creek, but rarely amounts to much
The normals record 5.5 inches of snow a year here, most likely in February. That is a real but marginal amount: enough that snow is part of the local record, not enough to define the winter.
A figure in this range usually reflects a handful of events that melt quickly rather than a season of accumulation; about 1 days a year record any measurable snow at all.
NOAA 1991-2020 normals. An average across thirty years can smooth away a single heavy winter, so a small annual figure does not mean a significant snowfall is impossible.
Frost Dates & Growing Season
First Fall Freeze
October 7
50% probability date
Last Spring Freeze
May 24
50% probability date
Growing Season
136 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
4,663
Higher = more heating needed
Cooling Degree Days
639
Higher = more cooling needed
Warmest Month
July
Coldest Month
December
Nationwide similar cities
Other rankable U.S. places outside AZ closest to Walnut Creek on two NOAA annual-normal axes (mean temperature and annual precipitation). Chip rows use distinct link sets.
Closest by average temperature
Nearest out-of-state peers by annual mean temperature (54°F here).
- Brookings, OR 54°F · 0.0°F off
- Dayton, OH 54°F · 0.0°F off
- Glenville, WV 54°F · 0.0°F off
- Hanksville, UT 54°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (14.8" here), excluding temperature-peer places.
- Great Falls, MT 14.8" · 0.0" off
- Union, OR 14.8" · 0.0" off
- Torrington, WY 14.8" · 0.0" off
- Baker, MT 14.7" · 0.0" off
Scarce-water calendar
Where Walnut Creek's limited precipitation lands
heating led · dry · mid swing
Walnut Creek's energy balance leans toward cold weather: 4,663 annual heating degree days against 639 for cooling. Its 36.5°F seasonal range still makes the monthly rows more useful than the annual average alone.
Only about 136 days are frost-free in a normal year. That short interval is consistent with the cold-season signal, but the measure does not predict the exact first or last freeze in any one year.
July and December mark the typical warm and cold ends of the calendar in Walnut Creek's middle-range seasonal profile. The measured spread is 36.5°F. The annual average is 54°F. Neither the annual mean nor one extreme month represents the full calendar on its own.
Walnut Creek's cold-season load does not imply a wet climate. Annual precipitation is 14.8 inches, which places the station in PlainClimate's dry range. Annual snowfall totals 5.5 inches. The snowfall and rainfall fields should be read separately rather than inferred from temperature.
Walnut Creek wettest normal
August
August concentrates the scarce annual total (14.8 inches).
Walnut Creek driest normal
June
June is typically driest; arid stations are defined by when water is absent, not by a four-season grid.
Questions about Walnut Creek's climate
How dry is Walnut Creek? ▼
How many days above 90°F does Walnut Creek get? ▼
How much energy does heating and cooling require in Walnut Creek? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Walnut Creek's primary station: WALNUT CREEK (USC00029158). For informational purposes only.
Place identity: U.S. Census Bureau 2024 Gazetteer places. The 2024 Census Gazetteer identifies the exact name-and-state match as a census-designated place (GEOID 0480825), not an incorporated municipality. Match rule for Walnut Creek: exact normalized name + state only, no fuzzy expansion, so nearby differently spelled facilities stay unmatched.
On this page every temperature, precipitation, and derived score for Walnut Creek comes from its primary NOAA station record. No figure on this page is typed in by an editor - each value is rendered from NOAA 1991-2020 U.S. Climate Normals. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 1991–2020 normals.