Photo: Quintin Soloviev · CC BY 4.0Pasco reaches 100° on about 11 days a year, more than 92% of U.S. towns
A typical July afternoon reaches 90°, a January night drops to 29°, and about 2 inches of snow falls in a normal winter.
A year in Pasco at a glance
Each month’s typical high and low, and what it brings.
What stands out about Pasco’s climate
Compared with towns across the U.S., with Pasco’s place in Washington beside it.
What a year in Pasco feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 216 frost-free days a year
In half of years the last 32° night comes by March 28 and the first by October 30. Day counts come from NOAA’s station at Pasco Tri Cities Airport, 0.2 miles from the city’s center point, at about the same height; frost dates and degree days from Kennewick, WA, 4 miles away.
The 2023 USDA map puts Pasco’s center in zone 7b: the coldest night of a typical winter, averaged over 1991–2020, reaches about 6°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 2 inches of snow a winter
Snow, measured at Ice Harbor Dam, WA, falls mostly in December. Precipitation (rain plus melted snow) adds up to 8 inches a year; December is the wettest month and August the driest. Rain or snow falls on about 97 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Pasco
82% of the work is heating. Months averaging under 55° run from October through April.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Kennewick, WA.
Living with Pasco’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
216 frost-free days in zone 7b. The last frost comes by Mar 28 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 30.
Months with highs of 62–84° and lows of 40° or more: April, May, June, September and October. 19 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Pasco from natural hazards, river flooding is the largest share (77%); heat waves, cold waves, winter storms and ice storms together are 15%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Pasco and its neighbors
Every town next door is within a degree of Pasco in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Pasco’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Pasco, WA | 29° | 90° | 8" | 2.0" |
| Alpine, TX | 30° | 90° | 15" | 2.2" |
| Sparks, NV | 25° | 92° | 8" | 6.8" |
| Sierra Vista, AZ | 32° | 91° | 14" | 0.4" |
| Alamogordo, NM | 27° | 93° | 11" | 2.4" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in Pasco averaged 1.0° warmer than the 1900s. The biggest change is in January (+3.7°).
A smaller shift than in 80% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Pasco compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Pasco’s place among Washington’s.
Pasco weather by month
Highs, lows and precipitation from NOAA’s grid at Pasco’s center; snow, wet days and snow on the ground from Ice Harbor Dam, WA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 41° | 29° | 1.1" | 0.2" | 14 | 0 | 22° – 42° |
| February | 48° | 30° | 0.7" | 0.2" | 10 | 1 | 26° – 44° |
| March | 58° | 35° | 0.7" | 0.1" | 10 | 0 | 36° – 51° |
| April | 66° | 40° | 0.7" | 0.0" | 9 | 0 | 48° – 59° |
| May | 75° | 48° | 0.8" | 0.0" | 8 | 0 | 57° – 66° |
| June | 81° | 54° | 0.6" | 0.0" | 6 | 0 | 63° – 75° |
| July | 90° | 59° | 0.2" | 0.0" | 3 | 0 | 68° – 79° |
| August | 89° | 58° | 0.2" | 0.0" | 2 | 0 | 69° – 76° |
| September | 80° | 50° | 0.3" | 0.0" | 4 | 0 | 62° – 68° |
| October | 65° | 41° | 0.7" | 0.0" | 8 | 0 | 49° – 58° |
| November | 50° | 33° | 0.9" | 0.1" | 12 | 0 | 36° – 47° |
| December | 41° | 29° | 1.1" | 1.4" | 13 | 1 | 27° – 40° |
| Year | 65° | 42° | 8.2" | 2.0" | 97 | 2 |
How much a month can swing
A normal is an average. January swings the most: from 1991 to 2020 its average ranged from 22° to 42°. September is the most reliable, staying within 7°.
Where Pasco’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Pasco’s center.
- Snow: Ice Harbor Dam, WA.
- Frost dates, heating and cooling: Kennewick, WA, 4 miles away.
- Freezing nights, 90° and 100° days: Pasco Tri Cities Airport, 0.2 miles from the city’s center point, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Pasco’s climate
What is the weather like in Pasco?
A typical July afternoon reaches 90°, a January night drops to 29°, and about 2 inches of snow falls in a normal winter. Milder January nights than 71% of U.S. towns; hotter July afternoons than 79% of U.S. towns.
How cold does it get in Pasco in winter?
December nights average 29°. About 112 nights a year reach 32° or below and 1 reach 0° or below. In the coldest December of the last 30 years the month averaged 27°.
How much snow does Pasco get?
About 2.0 inches in a normal winter at Ice Harbor Dam, WA, most of it in December, with snow on the ground about 2 days a year.
How hot does it get in Pasco?
July, with a typical high of 90° and a low of 59°. About 55 days a year reach 90° and 11 reach 100° (Kennewick, WA).
When is the first and last frost in Pasco?
In half of years the last spring frost (32°) comes by March 28 and the first fall frost by October 30, about 216 frost-free days, at Kennewick, WA.
What growing zone is Pasco in?
Zone 7b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 6°.
What is the best time of year to visit Pasco?
By one simple rule (highs of 62–84° and lows of 40° or more), April, May, June, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Pasco getting warmer?
Yes: 1991–2020 averaged 1.0° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 80% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Pasco.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.