Valencia Hall · Photo: Mrwrite · CC BY-SA 3.0Few U.S. towns have cooler summers than Day Valley
The coldest hours of a January night bottom out at 40° on average. Temperatures cover 40° across the year, low to high. Its January nights stay gentler than in 89% of U.S. towns. Plan time outside from March to November, when highs sit at 64–79°.
A year in Day Valley at a glance
Each month’s typical high and low, and what it brings.
What stands out about Day Valley’s climate
Compared with towns across the U.S., with Day Valley’s place in California beside it.
What a year in Day Valley feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 324 frost-free days a year
In half of years the last 32° night comes by January 28 and the first by December 13. Frost and day counts come from Watsonville Wtr Wks, CA, 8 miles away.
The 2023 USDA map puts Day Valley’s center in zone 9b: the coldest night of a typical winter, averaged over 1991–2020, reaches about 30°. 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 31 inches of rain a year
January is the wettest month and July the driest. Rain falls on about 65 days a year. Snow is rare: about 0.0" in a normal year at Santa Cruz, CA, so most winters see none.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Day Valley
95% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from November through March.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Watsonville Wtr Wks, CA.
Living with Day Valley’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
324 frost-free days in zone 9b. The last frost comes by Jan 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 Dec 13.
Months with highs of 62–84° and lows of 40° or more: March, April, May, June, July, August, September, October and November. 23 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Day Valley from natural hazards, earthquakes are the largest share (59%); heat waves, cold waves, winter storms and ice storms together are 1%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Day Valley and its neighbors
Corralitos the hottest July afternoons (80°, 2° warmer). Differences under a degree are within what the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Day Valley’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 |
|---|---|---|---|---|
| Day Valley, CA | 40° | 78° | 31" | 0.0" |
| Mercer Island, WA | 37° | 77° | 37" | 3.8" |
| Tualatin, OR | 36° | 81° | 40" | 1.0" |
| Makawao, HI | 53° | 75° | 23" | 0.0" |
| Swannanoa, NC | 27° | 83° | 48" | 2.1" |
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 Day Valley averaged 1.8° warmer than the 1900s. The biggest change is in January (+2.7°).
A bigger shift than in 82% 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 Day Valley compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Day Valley’s place among California’s.
Day Valley weather by month
Highs, lows and precipitation from NOAA’s grid at Day Valley’s center; snow, wet days and snow on the ground from Santa Cruz, CA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 61° | 40° | 6.4" | 0.0" | 11 | 0 | 47° – 55° |
| February | 62° | 41° | 5.9" | 0.0" | 11 | 0 | 48° – 57° |
| March | 64° | 43° | 4.6" | 0.0" | 10 | 0 | 49° – 59° |
| April | 67° | 44° | 2.0" | 0.0" | 6 | 0 | 52° – 60° |
| May | 71° | 48° | 0.8" | 0.0" | 4 | 0 | 56° – 64° |
| June | 76° | 51° | 0.2" | 0.0" | 1 | 0 | 60° – 66° |
| July | 78° | 55° | 0.0" | 0.0" | 1 | 0 | 63° – 70° |
| August | 79° | 55° | 0.0" | 0.0" | 1 | 0 | 65° – 72° |
| September | 79° | 54° | 0.1" | 0.0" | 1 | 0 | 63° – 71° |
| October | 75° | 49° | 1.2" | 0.0" | 4 | 0 | 59° – 67° |
| November | 66° | 44° | 3.1" | 0.0" | 7 | 0 | 48° – 58° |
| December | 60° | 40° | 6.2" | 0.0" | 10 | 0 | 46° – 53° |
| Year | 70° | 47° | 30.5" | 0.0" | 65 | 0 |
How much a month can swing
A normal is an average. March swings the most: from 1991 to 2020 its average ranged from 49° to 59°. June is the most reliable, staying within 6°.
Where Day Valley’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 Day Valley’s center.
- Snow: Santa Cruz, CA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Watsonville Wtr Wks, CA, 8 miles from the town’s center, 810 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 Day Valley’s climate
What is the weather like in Day Valley?
A typical July afternoon reaches 78°, a January night drops to 40°, and snow is almost unheard of. Milder January nights than 89% of U.S. towns; cooler July afternoons than 96% of U.S. towns.
How cold does it get in Day Valley in winter?
December nights average 40°. About 8 nights a year reach 32° or below. In the coldest December of the last 30 years the month averaged 46°.
How much snow does Day Valley get?
About 0.0 inches in a normal winter at Santa Cruz, CA, so most winters see none.
How hot does it get in Day Valley?
July, with a typical high of 78° and a low of 55°. About 7 days a year reach 90° (Watsonville Wtr Wks, CA).
When is the first and last frost in Day Valley?
In half of years the last spring frost (32°) comes by January 28 and the first fall frost by December 13, about 324 frost-free days, at Watsonville Wtr Wks, CA.
What growing zone is Day Valley in?
Zone 9b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 30°.
What is the best time of year to visit Day Valley?
By one simple rule (highs of 62–84° and lows of 40° or more), March, April, May, June, July, August, September, October and November. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Day Valley getting warmer?
Yes: 1991–2020 averaged 1.8° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 82% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Day Valley.
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.