Pomeroy, Washington climate: Normal weather by month, frost dates and records
Pomeroy's normal year runs from 26°F December nights to 85°F July afternoons, with 17.6 inches of precipitation and 8 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 9.9°C, December lows of −3°C, July highs of 30°C, 448 mm of precipitation a year.
- NOAA stationPomeroy
- Station IDUSC00456610
- Location46.47°N 117.59°W
- Elevation1,934 ft (590 m)
- Population1,471
On October 23, the normal high in Pomeroy is 57°F and the normal low 36°F, and the chance of measurable rain or snow is 28%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Pomeroy.
- Jan 40° 27°
- Feb 45° 28°
- Mar 52° 33°
- Apr 59° 37°
- May 67° 44°
- Jun 74° 49°
- Jul 85° 53°
- Aug 85° 53°
- Sep 75° 45°
- Oct 61° 37°
- Nov 48° 32°
- Dec 40° 26°
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 Pomeroy each month?
July is the warmest month, with normal highs of 85°F; December the coldest, with normal lows of 26°F. The most precipitation falls in November (2.32 in), the least in July (0.46 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 40°F | 27°F | 33.8°F | 2.04 | 2.2 | 12 | <1 | 23 | 9 h |
| February | 45°F | 28°F | 36.4°F | 1.62 | 1.2 | 10 | <1 | 20 | 10 h 20 min |
| March | 52°F | 33°F | 42.3°F | 2.08 | 0.8 | 12 | <1 | 18 | 11 h 50 min |
| April | 59°F | 37°F | 47.9°F | 1.67 | 0.1 | 10 | <1 | 9 | 13 h 30 min |
| May | 67°F | 44°F | 55.6°F | 1.60 | 0.0 | 9 | <1 | 3 | 15 h |
| June | 74°F | 49°F | 61.5°F | 1.15 | 0.0 | 7 | 2 | <1 | 15 h 50 min |
| July | 85°F | 53°F | 69.0°F | 0.46 | 0.0 | 3 | 12 | <1 | 15 h 30 min |
| August | 85°F | 53°F | 69.0°F | 0.53 | 0.0 | 3 | 11 | <1 | 14 h 10 min |
| September | 75°F | 45°F | 60.3°F | 0.58 | 0.0 | 4 | 2 | 1 | 12 h 40 min |
| October | 61°F | 37°F | 48.9°F | 1.31 | 0.0 | 7 | <1 | 10 | 11 h |
| November | 48°F | 32°F | 39.6°F | 2.32 | 0.5 | 13 | <1 | 17 | 9 h 30 min |
| December | 40°F | 26°F | 32.9°F | 2.27 | 3.6 | 12 | <1 | 24 | 8 h 40 min |
| Year (annual) | 61°F | 39°F | 49.8°F | 17.63 | 8.4 | 102 | 27 | 125 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 5°C | −3°C | 1.0°C | 52 mm | 6 cm |
| February | 7°C | −2°C | 2.4°C | 41 mm | 3 cm |
| March | 11°C | 0°C | 5.7°C | 53 mm | 2 cm |
| April | 15°C | 3°C | 8.8°C | 42 mm | 0 cm |
| May | 20°C | 7°C | 13.1°C | 41 mm | 0 cm |
| June | 24°C | 9°C | 16.4°C | 29 mm | 0 cm |
| July | 30°C | 12°C | 20.6°C | 12 mm | 0 cm |
| August | 30°C | 12°C | 20.6°C | 13 mm | 0 cm |
| September | 24°C | 7°C | 15.7°C | 15 mm | 0 cm |
| October | 16°C | 3°C | 9.4°C | 33 mm | 0 cm |
| November | 9°C | 0°C | 4.2°C | 59 mm | 1 cm |
| December | 4°C | −3°C | 0.5°C | 58 mm | 9 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00456610; 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 Pomeroy?
Normal highs sit between 65°F and 85°F in May, June and September. Of those, September has the fewest days with rain (4).
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 USC00456610.
When is the last frost in Pomeroy?
In Pomeroy, the last spring frost (32°F) comes after May 2 in half of years and after May 19 in one year in ten; the first autumn frost comes before October 4 in half of years and before September 17 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 21 year in 10 after May 19; 9 in 10 after April 15
- First autumn frost, half of years before
- October 41 year in 10 before September 17; 9 in 10 before October 24
NOAA puts the median frost-free season at 155 days, and the season without a hard freeze (28°F) at 189 days.
A hard freeze (28°F) comes after April 11 in half of springs and before October 19 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Pomeroy in zone 7a in ZIP code 99347, the nearest ZIP area.
Frost dates for every NOAA station in Washington · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00456610; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. 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 Pomeroy?
In a normal year in Pomeroy, 27 days a year reach 90°F (2 of them 100°F or more), 125 nights fall to 32°F or colder and 102 days bring measurable precipitation.
- Days at 90°F or more
- 27a normal year
- Days at 100°F or more
- 2a normal year
- Nights at 32°F or colder
- 125a normal year
- Days that stay below freezing
- 17high of 32°F or less
- Days with 0.01 inch of precipitation
- 102a normal year
- Days with 1 inch of snow or more
- 3a normal year
The highest temperature in this station's record (since 1891) is 112°F, on July 26, 1928; the lowest is −27°F, on December 30, 1968.
The wettest calendar year on that record is 2012, with 24.81 in; the snowiest season is 2008–09, with 47.2 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00456610; records: ACIS (NOAA Regional Climate Centers), station USC00456610. Records use complete months only; a month missing more than three days is left out.
How sunny is Pomeroy?
Over a year 76% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Pomeroy, 4.0 kWh per square metre a day. July is the sunniest month (91%) and December the cloudiest (55%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 59% | 1.3 |
| February | 64% | 2.2 |
| March | 64% | 3.3 |
| April | 70% | 4.8 |
| May | 75% | 6.0 |
| June | 78% | 6.8 |
| July | 91% | 7.5 |
| August | 88% | 6.2 |
| September | 83% | 4.5 |
| October | 73% | 2.8 |
| November | 61% | 1.5 |
| December | 55% | 1.0 |
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 Pomeroy need?
A normal year in Pomeroy brings 5,928 heating degree days, 10% more than the median U.S. place (5,373), and 396 cooling degree days, 56% fewer than the median (908). Eight months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 2,195 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 969 | 0 |
| February | 801 | 0 |
| March | 704 | 0 |
| April | 512 | 0 |
| May | 303 | 12 |
| June | 143 | 37 |
| July | 31 | 155 |
| August | 35 | 157 |
| September | 175 | 34 |
| October | 499 | 1 |
| November | 762 | 0 |
| December | 995 | 0 |
| Year (annual) | 5,928 | 396 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00456610. 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 Pomeroy's climate compare?
Pomeroy is warmer than 34 of the other 95 places with their own NOAA record in Washington, and wetter than 35. Across the 7,247 U.S. stations with normals, its annual mean of 49.8°F is warmer than 39%.
In the Köppen classification computed from these normals, Pomeroy is Csb: temperate, dry-summer, warm summer. 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 Pomeroy share this climate record?
Pataha has no NOAA station with 1991-2020 normals of its 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.
- Pataha, WA108 people · 2 mi E
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 Pomeroy's climate
What is the coldest month in Pomeroy?
December, with a normal high of 40°F and a normal low of 26°F. The warmest is July (85°F by day, 53°F at night).
Does it snow in Pomeroy?
Yes: 8 inches in a normal year, falling on 5 days with 0.1 inch or more, the most in December (3.6 inches).
What is the rainiest month in Pomeroy?
November, with 2.32 in of precipitation in a normal year; the driest is July with 0.46 in.
What plant hardiness zone is Pomeroy in?
The USDA's 2023 map puts Pomeroy in zone 7a in ZIP code 99347, the nearest ZIP area.
How late can frost come in Pomeroy?
In half of years the last 32°F night comes after May 2; in one year in ten it comes after May 19. Waiting until May 19 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Washington climateThe statewide normals and every place in the state
- Dayton, WA22 miles from this station, 51.1°F a year
- LaCrosse, WA28 miles from this station, 50.1°F a year
- Lewiston, ID28 miles from this station, 53.8°F a year
- Pullman, WA30 miles from this station, 48.6°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made