Penryn, California Weather
Summer heat deepens across the valleys. Day 15 of summer. Read this microseason across nine climate regions →
Penryn weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 5Overcast——90°64°—
- MondayJul 6Overcast——91°60°+1°
- TuesdayJul 7Overcast——93°55°+2°
- WednesdayJul 8Clear——95°57°+2°
- ThursdayJul 9Clear——100°61°+5°
- FridayJul 10Overcast——101°63°+1°
- SaturdayJul 11Overcast——104°68°+3°
AQI 29 (Good), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 7.0 µg/m³, PM10 at 9.7 µg/m³ — typical background levels with no transport signature.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
PM × Wind × Precip
PM2.5 at 7.0 µg/m³, PM10 at 9.7 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.72
- Wind
- light
- Recent rain
- 0h in last 6h
- Pattern
- background
Trends
Seven days of AQI and PM2.5.
Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).








































If the first of July be rainy weather, 'twill rain more or less for four weeks together.
- Moonrise
- 11:24 PM
- Moonset
- 11:23 AM
- In sign
- ♓︎ Pisces
Summer heat deepens across the valleys
Penryn at a glance
- Today vs. normal: 3°F above the seasonal normal for this latitude
- Last frost: April 9 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
ZIP code: 95663
16-Day Forecast — Penryn
- Sun90°64°2%
- Mon91°60°1%
- Tue93°55°0%
- Wed95°57°0%
- Thu100°61°0%
- Fri101°63°0%
- Sat104°68°0%
- Sun86°73°1%
- Mon101°65°3%
- Tue109°69°4%
- Wed107°69°2%
- Thu108°70°3%
- Fri110°75°10%
- Sat107°73°10%
- Sun103°72°11%
- Mon102°65°6%
Forecast data from Open-Meteo (CC BY 4.0).
Right now in the garden
Peak growing season
As of July 5, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.
Microseason · July 1–5
Summer heat deepens across the valleys
Inland temperatures exceed 95°F regularly; fire danger reaches moderate to high across most of the region.
Day 186 of 365 · Wedge 37 of 72
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | — | — |
| February | — | — |
| March | — | — |
| April | lettuce, peas, spinach, radishes | — |
| May | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| June | tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| July | tomatoes, peppers, beans, squash | tomatoes, beans, summer squash |
| August | — | tomatoes, beans, summer squash |
| September | fall brassicas, garlic (overwinter), carrots | tomatoes, beans, summer squash |
| October | fall brassicas, garlic (overwinter), carrots | winter squash, tomatoes (last) |
| November | — | — |
| December | — | — |
A year in weather
The year in Penryn tops out in July (~76°F) and dips lowest in December (~46°F), with January wettest at 3.7 inches and July driest at 0.0 inches.
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 47° | 3.7″ | 6 |
| February | 50° | 3.5″ | 7 |
| March | 54° | 2.6″ | 6 |
| April | 59° | 1.2″ | 3 |
| May | 66° | 0.6″ | 2 |
| June | 73° | 0.2″ | 1 |
| July | 76° | 0.0″ | 0 |
| August | 75° | 0.1″ | 0 |
| September | 72° | 0.1″ | 0 |
| October | 64° | 0.8″ | 2 |
| November | 53° | 1.8″ | 4 |
| December | 46° | 3.3″ | 7 |
Frequently asked
- When does it freeze in Penryn?
- In Penryn, expect the last spring frost near mid-April; Penryn's first autumn frost comes around mid-November.
- What is the rainy season in Penryn?
- January is the wettest month in Penryn, about 3.7 inches on average; the year totals roughly 18 inches.
- What is the warmest month in Penryn?
- July is Penryn's warmest month, averaging about 76°F.
- What is the coldest month in Penryn?
- Penryn bottoms out in December, with a mean near 46°F.
- When can I start a vegetable garden in Penryn?
- Penryn's last frost (mid-April) cues hardy greens; in Penryn, hold heat-lovers two weeks past.
- How many rainy days does Penryn get?
- Penryn averages about 36 days with measurable rain or snow each year.
- What hardiness zone is Penryn?
- Penryn sits in the USDA zone set by December lows near 46°F; the USDA ZIP tool gives the band.
- What is the 10-day forecast for Penryn?
- Penryn's extended outlook — daily high and low temperatures and precipitation chances for each upcoming day — is in the daily forecast above.
- Will it rain this week in Penryn?
- See this week's day-by-day rain chances for Penryn in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Penryn?
- Current conditions for Penryn and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Penryn forecast updated?
- The Penryn forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Penryn?
- Today's sunrise and sunset times for Penryn are in the Almanac section above, along with civil dawn, civil dusk, and day length. Day length is longest near the summer solstice and shortest near the winter solstice.
- How accurate is the weather forecast for Penryn?
- The next few days in Penryn's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Climate
Penryn's hot-summer Mediterranean climate in California pairs 47°F Januarys with 76°F Julys, 29°F apart across the seasons.
Rain and snow bring Penryn roughly 18 inches a year across approximately 36 measurable-precipitation days.
At 38.8°N, Penryn's 29°F summer-to-winter swing sets when Penryn's gardens wake and when frost returns.
ZIP codes in Penryn
- 95663
- 95650