Climate Comfort Score
48/100
Moderate
NOAA 1991–2020 normals 53°F annual avg Public-domain federal data
Prosser, WA Climate
Annual temperature, rainfall, and a comfort score, sourced from NOAA NCEI's 1991–2020 normals →
- 53°F
- Avg annual temp
- 48/100
- Comfort score
- 8.7"
- Annual precip
- 191d
- Growing season
30-year climate normals from 1 weather station (1991-2020).
The climate verdict for Prosser
Prosser, Washington averages 53°F a year and scores 48/100 on the comfort index - moderate, milder than 18% of U.S. cities.
- 53°F
- average temperature, NOAA 1991-2020 normal
- 48/100
- comfort score, milder than 18% of U.S. cities
- 8.7"
- annual precipitation
- 191 days
- frost-free growing season
Based on NOAA U.S. Climate Normals (1991–2020) - 30-year averages describing the typical year, not a forecast.
Avg Temperature
53°F (12°C)
Avg High
65°F
Avg Low
42°F
Annual Precip
8.7"
Comfort Score
48/100
Moderate
Avg Annual Temperature
53°F
30-year mean (NOAA NCEI)
Annual Precipitation
8.7"
Liquid-equivalent total
Comfort score vs national 100-point ceiling (Prosser) 48.0%
National median (63)
PlainClimate composite, temperature mildness, humidity, precipitation, extreme-weather frequency. Moderate for the Prosser area.
How Prosser compares to every U.S. city
Prosser's comfort score vs. all U.S. cities
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
48 Top 82% higher than 18% of 6,915 US cities
Each bar is a band; taller bars hold more US cities. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020
Warming context for Prosser
MethodologyThe chart below traces how the U.S. land temperature anomaly has moved against the global mean since 1900. For Prosser, the NOAA 1991-2020 normal captures average conditions across that spread - notably, the most recent decade runs warmer than the 30-year mean itself.
- United States land mean (NOAA NCEI) +0.11 °C/decade
- Global anomaly (NASA GISTEMP) +0.11 °C/decade
- Paris Agreement thresholds 1.5°C / 2.0°C
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|
| January | 40°F (5°C) | 27°F (-3°C) | 34°F (1°C) | 1.2" | 24.5 | 0.0 |
| February | 47°F (8°C) | 29°F (-2°C) | 38°F (3°C) | 0.9" | 20.7 | 0.0 |
| March | 56°F (13°C) | 35°F (2°C) | 45°F (7°C) | 0.7" | 11.8 | 0.0 |
| April | 65°F (18°C) | 40°F (4°C) | 52°F (11°C) | 0.7" | 4.2 | 0.0 |
| May | 74°F (23°C) | 48°F (9°C) | 61°F (16°C) | 0.9" | 0.3 | 2.0 |
| June | 81°F (27°C) | 54°F (12°C) | 67°F (20°C) | 0.7" | 0.0 | 5.6 |
| July | 90°F (32°C) | 60°F (15°C) | 75°F (24°C) | 0.2" | 0.0 | 17.9 |
| August | 89°F (32°C) | 58°F (14°C) | 73°F (23°C) | 0.2" | 0.0 | 17.3 |
| September | 80°F (27°C) | 50°F (10°C) | 65°F (18°C) | 0.3" | 0.4 | 3.8 |
| October | 65°F (18°C) | 41°F (5°C) | 53°F (12°C) | 0.8" | 4.2 | 0.0 |
| November | 49°F (10°C) | 32°F (0°C) | 41°F (5°C) | 0.9" | 17.5 | 0.0 |
| December | 40°F (4°C) | 26°F (-3°C) | 33°F (0°C) | 1.3" | 25.0 | 0.0 |
Monthly Precipitation
Average monthly rainfall
January 1.2"
8.3 days with precipitation
February 0.9"
5.9 days with precipitation
March 0.7"
5.9 days with precipitation
April 0.7"
5.2 days with precipitation
May 0.9"
5.8 days with precipitation
June 0.7"
3.7 days with precipitation
July 0.2"
1.7 days with precipitation
August 0.2"
1.5 days with precipitation
September 0.3"
2.7 days with precipitation
October 0.8"
5.7 days with precipitation
November 0.9"
7.1 days with precipitation
December 1.3"
8.3 days with precipitation
Frost Dates & Growing Season
First Fall Freeze
October 22
50% probability date
Last Spring Freeze
April 14
50% probability date
Growing Season
191 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
5,172
Higher = more heating needed
Cooling Degree Days
839
Higher = more cooling needed
Warmest Month
July
Coldest Month
December
What Prosser's climate means for you
Prosser runs 53°F a year - peaking in July, coldest in December.
- Gardeners get about 191 frost-free days, with the last spring freeze near April 14 - plan the planting calendar around it, not the regional average.
- Energy bills track 5,172 heating and 839 cooling degree days a year, higher means the furnace or AC runs more.
- Comparing places to live? Line this city up against nearby cities and the national rankings. See rankings
These are 30-year NOAA normals (1991–2020) - the typical year, not a forecast for any specific season.
Climate Guides
Climate Insight: Prosser, WA
In Prosser, Washington, the NOAA 1991–2020 climate normals put the annual average temperature at 53°F, ranging from a mean daily high of 65°F to a mean daily low of 42°F. July is typically the warmest month of the year, while December is the coldest. As thirty-year averages computed from station USC00456768, these numbers smooth out year-to-year noise into a working baseline for a typical month.
Prosser averages 8.7 inches of precipitation a year, predominantly as rainfall, and that matters as much to daily life here as temperature does. The frost-free season averages 191 days, which directly shapes the planting calendar and growing potential for the area, with the last spring freeze near April 14 and the first fall freeze near October 22. As for energy demand, 5,172 heating degree days and 839 cooling degree days tell the story of how often furnaces and air conditioners run during a normal year.
On PlainClimate's composite comfort index, Prosser scores 48/100 (Moderate), a blended measure that weighs temperature mildness, precipitation moderation, and extreme-weather frequency against one another. For planning purposes, look to the monthly tables above: shoulder seasons bring the mildest highs and lows, summer brings July-driven heat, and deep winter brings December-driven cold. Treat every figure here as a thirty-year average rather than a forecast - individual years routinely run warmer, cooler, wetter, or drier than the normal.
Frequently Asked Questions
What is the average temperature in Prosser, WA? ▼
The average annual temperature in Prosser, Washington is 53°F. The warmest month averages 90°F (32°C) and the coldest averages 26°F (-3°C).
How much rain does Prosser get? ▼
Prosser receives 8.7 inches of precipitation annually. Based on NOAA 30-year climate normals (1991-2020).
What is the comfort score for Prosser? ▼
Prosser has a climate comfort score of 48/100 (Moderate), milder than 18% of U.S. cities in the PlainClimate database.
When is the growing season in Prosser? ▼
Prosser has approximately 191 frost-free days per year, with the last spring freeze around April 14 and the first fall freeze around October 22.
How much energy does heating and cooling require in Prosser? ▼
Prosser has 5,172 heating degree days and 839 cooling degree days annually, a heating-dominated climate. See our <a href="/guides/reading-weather-data/" class="underline hover:text-brand-600">guide to reading weather data</a> for what these figures mean.
Where does this Prosser climate data come from? ▼
NOAA U.S. Climate Normals v1.0.1 (1991-2020), from weather station USC00456768 near Prosser.
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). Station: USC00456768. For informational purposes only.
Read our methodology - how this data is sourced, computed, and verified.
Related
Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainClimate Editorial
Every figure on PlainClimate is rendered directly from NOAA 1991-2020 U.S. Climate Normals data, no number is typed in by an editor. This page draws directly on NOAA 1991-2020 U.S. Climate Normals data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.