Grand Terrace, California Weather
Summer heat deepens across the valleys. Day 15 of summer. Read this microseason across nine climate regions →
Grand Terrace weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 5Clear——92°66°—
- MondayJul 6Clear——93°61°+1°
- TuesdayJul 7Clear——97°65°+4°
- WednesdayJul 8Clear——101°75°+4°
- ThursdayJul 9Clear——103°78°+2°
- FridayJul 10Overcast——100°78°-3°
- SaturdayJul 11Overcast——94°76°-6°
AQI 36 (Good), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 8.4 µg/m³ (AQI 47) with a 0.71 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
Ozone × UV × Sky
Ozone at AQI 35 now. With UV 12 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 56 around 1 PM.
- Present
- AQI 35
- UV peak
- 12.0 at 1 PM
- Sky at peak
- clear
- Projected peak
- AQI 56
PM × Wind × Precip
PM2.5 at 8.4 µg/m³ (AQI 47) with a 0.71 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.71
- Wind
- light
- Recent rain
- 0h in last 6h
- Pattern
- stagnant smoke
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
- 11:05 PM
- Moonset
- 11:08 AM
- In sign
- ♓︎ Pisces
Summer heat deepens across the valleys
Grand Terrace at a glance
- Today vs. normal: 6°F above the seasonal normal for this latitude
- Last frost: March 11 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
ZIP code: 92313
16-Day Forecast — Grand Terrace
- Sun92°66°1%
- Mon93°61°1%
- Tue97°65°0%
- Wed101°75°0%
- Thu103°78°0%
- Fri100°78°0%
- Sat94°76°1%
- Sun91°75°1%
- Mon102°78°8%
- Tue105°83°14%
- Wed103°84°7%
- Thu106°83°13%
- Fri104°86°14%
- Sat100°84°12%
- Sun106°84°19%
- Mon106°83°18%
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 | lettuce, peas, spinach, radishes | — |
| April | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | — |
| May | tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| June | tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| July | — | tomatoes, beans, summer squash |
| August | — | tomatoes, beans, summer squash |
| September | — | tomatoes, beans, summer squash |
| October | fall brassicas, garlic (overwinter), carrots | winter squash, tomatoes (last) |
| November | fall brassicas, garlic (overwinter), carrots | — |
| December | — | — |
A year in weather
In Grand Terrace, August runs warmest near 80°F and December coldest around 50°F, while February is the wettest month (2.7 inches) and June the driest (0.0 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 50° | 2.5″ | 11 |
| February | 52° | 2.7″ | 10 |
| March | 54° | 2.5″ | 13 |
| April | 60° | 1.2″ | 9 |
| May | 67° | 0.4″ | 6 |
| June | 73° | 0.0″ | 2 |
| July | 79° | 0.4″ | 3 |
| August | 80° | 0.3″ | 3 |
| September | 76° | 0.3″ | 3 |
| October | 68° | 0.5″ | 5 |
| November | 57° | 1.2″ | 7 |
| December | 50° | 2.2″ | 10 |
Regional context
Per NOAA NCEI 1991-2020 normals, Grand Terrace runs from a 50°F January mean to 79°F in July, a 29°F seasonal spread, with near 14.3 inches of precipitation across about 81 wet days.
Grand Terrace's moisture rides winter storm tracks: February brings 2.7 inches over 10.2 wet days, while June sees only 0.0 inches across 1.8 days in the dry warm season. It is a winter-storm rhythm Grand Terrace shares with places like Highgrove, CA, Colton, CA and Loma Linda, CA.
With a coldest-month mean of 50°F, Grand Terrace stays mostly frost-free and grows year-round. The August peak near 80°F is Grand Terrace's real limit, pushing cool-season vegetables to spring and fall. Grand Terrace's coastal lots stay 4-7°F milder overnight than Grand Terrace's inland parcels.
Similar climates: Highgrove, CA, Colton, CA, Loma Linda, CA, Bloomington, CA, Rialto, CA.
Frequently asked
- When does it freeze in Grand Terrace?
- In Grand Terrace, expect the last spring frost near mid-March; Grand Terrace's first autumn frost comes around mid-December.
- What is the rainy season in Grand Terrace?
- February is the wettest month in Grand Terrace, about 2.7 inches on average; the year totals roughly 14 inches.
- What is the warmest month in Grand Terrace?
- August is Grand Terrace's warmest month, averaging about 80°F.
- What is the coldest month in Grand Terrace?
- Grand Terrace bottoms out in December, with a mean near 50°F.
- When can I start a vegetable garden in Grand Terrace?
- Frost-hardy sowings begin at mid-March in Grand Terrace; warm-season starts follow two weeks on.
- How many rainy days does Grand Terrace get?
- Grand Terrace records around 81 days of measurable precipitation annually.
- What hardiness zone is Grand Terrace?
- Grand Terrace's hardiness zone tracks its winter low; with December near 50°F, check the USDA ZIP map for the exact zone.
- What is the 10-day forecast for Grand Terrace?
- Grand Terrace'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 Grand Terrace?
- See this week's day-by-day rain chances for Grand Terrace in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Grand Terrace?
- Current conditions for Grand Terrace and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Grand Terrace forecast updated?
- The Grand Terrace forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Grand Terrace?
- Today's sunrise and sunset times for Grand Terrace 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 Grand Terrace?
- The next few days in Grand Terrace's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Climate
Grand Terrace, California occupies a hot-summer Mediterranean zone, with January means near 50°F and July around 79°F — a 29°F swing.
Across the year, Grand Terrace collects about 14 inches of precipitation over roughly 81 days with measurable rain or snow.
The 29°F gap between Grand Terrace's summer and winter, at 34.0°N, shapes Grand Terrace's frost calendar.
ZIP codes in Grand Terrace
- 92313