Photo: Tedder · CC BY-SA 4.0Precipitation in Oroville trails that of 95% of U.S. towns: 13 inches a year
The warmest part of a July day comes in at 89° on average. By July afternoons alone, it runs hotter than 71% of U.S. towns. Since 1901–2000, the year has warmed by 1.3°, most of all in January. Plan time outside for May, June and September, when highs sit at 74–80°.
A year in Oroville at a glance
Each month’s typical high and low, and what it brings.
What stands out about Oroville’s climate
Compared with towns across the U.S., with Oroville’s place in Washington beside it.
What a year in Oroville feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 168 frost-free days a year
In half of years the last 32° night comes by April 26 and the first by October 10. Frost and day counts come from NOAA’s station at Tonasket 4 Nne, WA, 11 miles from the town’s center, at about the same height.
The 2023 USDA map puts Oroville’s center in zone 7a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 4°. 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 13 inches of rain a year
June is the wettest month and August the driest.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Oroville
92% of the work is heating, so the furnace matters far more than the air conditioner. 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 Tonasket 4 Nne, WA.
Living with Oroville’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
168 frost-free days in zone 7a. The last frost comes by Apr 26 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 10.
Months with highs of 62–84° and lows of 40° or more: May, June and September. 1.0 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Oroville from natural hazards, avalanches are the largest share (36%); heat waves, cold waves, winter storms and ice storms together are 7%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Oroville and similar climates
TownRatings has no climate map of the towns around Oroville yet.
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
Warmer than it used to be
The last 30 years in Oroville averaged 1.3° warmer than the 1900s. The biggest change is in January (+3.9°).
A smaller shift than in 52% 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 Oroville compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Oroville’s place among Washington’s.
Oroville weather by month
Highs, lows and precipitation from NOAA’s grid at Oroville’s center. 1991–2020 normals.
| Month | High | Low | Rain + melt | 30-yr range |
|---|---|---|---|---|
| January | 35° | 25° | 1.2" | 22° – 37° |
| February | 42° | 27° | 0.8" | 24° – 41° |
| March | 54° | 33° | 1.0" | 38° – 49° |
| April | 64° | 39° | 1.0" | 46° – 59° |
| May | 74° | 47° | 1.5" | 56° – 67° |
| June | 80° | 54° | 1.6" | 63° – 74° |
| July | 89° | 59° | 0.9" | 67° – 78° |
| August | 88° | 58° | 0.7" | 67° – 76° |
| September | 78° | 49° | 0.8" | 60° – 68° |
| October | 61° | 39° | 1.0" | 46° – 55° |
| November | 45° | 32° | 1.2" | 33° – 46° |
| December | 35° | 25° | 1.4" | 23° – 36° |
| Year | 62° | 41° | 13.0" |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 24° to 41°. September is the most reliable, staying within 8°.
Where Oroville’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 Oroville’s center.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Tonasket 4 Nne, WA, 11 miles from the town’s center, 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 Oroville’s climate
What is the weather like in Oroville?
A typical July afternoon reaches 89°, a January night drops to 25°. Milder January nights than 63% of U.S. towns; hotter July afternoons than 71% of U.S. towns.
How cold does it get in Oroville in winter?
January nights average 25°. About 134 nights a year reach 32° or below and 2 reach 0° or below. In the coldest January of the last 30 years the month averaged 22°.
How hot does it get in Oroville?
July, with a typical high of 89° and a low of 59°. About 30 days a year reach 90° and 2 reach 100° (Tonasket 4 Nne, WA).
When is the first and last frost in Oroville?
In half of years the last spring frost (32°) comes by April 26 and the first fall frost by October 10, about 168 frost-free days, at Tonasket 4 Nne, WA.
What growing zone is Oroville in?
Zone 7a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 4°.
What is the best time of year to visit Oroville?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Oroville getting warmer?
Yes: 1991–2020 averaged 1.3° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 52% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Oroville.
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.