Lake Riverside’s winters are milder but snowier than most of the U.S.
A typical July afternoon reaches 92°, a January night drops to 37°, and about 26 inches of snow falls in a normal winter.
A year in Lake Riverside at a glance
Each month’s typical high and low, and what it brings.
What stands out about Lake Riverside’s climate
Compared with towns across the U.S., with Lake Riverside’s place in California beside it.
What a year in Lake Riverside feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 189 frost-free days a year
In half of years the last 32° night comes by April 18 and the first by October 26. Frost and day counts come from Henshaw Dam, CA, 20 miles away.
The 2023 USDA map puts Lake Riverside’s center in zone 9a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 25°. 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 26 inches of snow a winter
Snow, measured at Palomar Mtn Obsy, CA, falls mostly in February. Precipitation (rain plus melted snow) adds up to 20 inches a year; February is the wettest month and June the driest. Rain or snow falls on about 42 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Lake Riverside
82% of the work is heating. Months averaging under 55° run from November 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 Henshaw Dam, CA.
Living with Lake Riverside’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
189 frost-free days in zone 9a. The last frost comes by Apr 18 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 26.
Months with highs of 62–84° and lows of 40° or more: April, May, October and November. 3.1 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Lake Riverside from natural hazards, wildfire is the largest share (85%). Normals are averages; the hazards page covers the extremes.
Natural hazards →Lake Riverside and similar climates
TownRatings has no climate map of the towns around Lake Riverside yet.
Climates most like Lake Riverside’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 |
|---|---|---|---|---|
| Lake Riverside, CA | 37° | 92° | 20" | 26" |
| Payson, AZ | 30° | 92° | 20" | 19" |
| Lewiston, ID | 30° | 92° | 14" | 13" |
| Walla Walla, WA | 30° | 91° | 16" | 9.0" |
| Pendleton, OR | 28° | 90° | 14" | 16" |
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 Lake Riverside averaged 2.0° warmer than the 1900s. The biggest change is in January (+3.0°).
A bigger shift than in 91% 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 Lake Riverside compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Lake Riverside’s place among California’s.
Lake Riverside weather by month
Highs, lows and precipitation from NOAA’s grid at Lake Riverside’s center; snow, wet days and snow on the ground from Palomar Mtn Obsy, CA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 60° | 37° | 4.0" | 6.2" | 7 | 44° – 55° |
| February | 60° | 37° | 4.8" | 10.6" | 8 | 41° – 57° |
| March | 64° | 39° | 3.1" | 3.1" | 6 | 43° – 59° |
| April | 69° | 41° | 1.3" | 3.5" | 4 | 49° – 59° |
| May | 76° | 46° | 0.7" | 0.0" | 2 | 54° – 68° |
| June | 85° | 52° | 0.1" | 0.0" | 0 | 62° – 74° |
| July | 92° | 59° | 0.2" | 0.0" | 1 | 70° – 80° |
| August | 93° | 60° | 0.2" | 0.0" | 1 | 73° – 79° |
| September | 87° | 56° | 0.4" | 0.0" | 1 | 68° – 76° |
| October | 77° | 49° | 0.8" | 0.0" | 2 | 59° – 69° |
| November | 67° | 41° | 1.5" | 0.4" | 3 | 45° – 60° |
| December | 59° | 36° | 3.4" | 2.4" | 6 | 43° – 55° |
| Year | 74° | 46° | 20.4" | 26.2" | 42 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 41° to 57°. August is the most reliable, staying within 6°.
Where Lake Riverside’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 Lake Riverside’s center.
- Snow: Palomar Mtn Obsy, CA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Henshaw Dam, CA, 20 miles from the town’s center, 700 ft lower; no station nearby passes every check; this is the nearest one in the same valley, flagged above.
- 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 Lake Riverside’s climate
What is the weather like in Lake Riverside?
A typical July afternoon reaches 92°, a January night drops to 37°, and about 26 inches of snow falls in a normal winter. Milder January nights than 84% of U.S. towns; hotter July afternoons than 85% of U.S. towns.
How cold does it get in Lake Riverside in winter?
December nights average 36°. About 105 nights a year reach 32° or below. In the coldest December of the last 30 years the month averaged 43°.
How much snow does Lake Riverside get?
About 26 inches in a normal winter at Palomar Mtn Obsy, CA, most of it in February.
How hot does it get in Lake Riverside?
July, with a typical high of 92° and a low of 59°. About 88 days a year reach 90° and 14 reach 100° (Henshaw Dam, CA).
When is the first and last frost in Lake Riverside?
In half of years the last spring frost (32°) comes by April 18 and the first fall frost by October 26, about 189 frost-free days, at Henshaw Dam, CA.
What growing zone is Lake Riverside in?
Zone 9a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 25°.
What is the best time of year to visit Lake Riverside?
By one simple rule (highs of 62–84° and lows of 40° or more), April, May, October and November. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Lake Riverside getting warmer?
Yes: 1991–2020 averaged 2.0° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 91% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Lake Riverside.
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.