Lake San Marcos, California Weather
Summer heat deepens across the valleys. Day 15 of summer. Read this microseason across nine climate regions →
Lake San Marcos weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 5Foggy——77°65°—
- MondayJul 6Foggy——77°62°0°
- TuesdayJul 7Foggy——80°59°+3°
- WednesdayJul 8Clear——84°59°+4°
- ThursdayJul 9Clear——84°61°0°
- FridayJul 10Overcast——85°60°+1°
- SaturdayJul 11Overcast——80°63°-5°
AQI 45 (Good), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 11.9 µg/m³ (AQI 56), ratio 0.70 with 7 mph wind — characteristic of long-range haze transport rather than a local source.
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 41 now. With UV 11 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 62 around 1 PM.
- Present
- AQI 41
- UV peak
- 11.4 at 1 PM
- Sky at peak
- clear
- Projected peak
- AQI 62
PM × Wind × Precip
PM2.5 at 11.9 µg/m³ (AQI 56), ratio 0.70 with 7 mph wind — characteristic of long-range haze transport rather than a local source.
- PM2.5/PM10
- 0.70
- Wind
- light
- Recent rain
- 0h in last 6h
- Pattern
- transport
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
- 11:04 PM
- Moonset
- 11:08 AM
- In sign
- ♓︎ Pisces
Summer heat deepens across the valleys
Lake San Marcos at a glance
- Today vs. normal: 3°F below the seasonal normal for this latitude
- Last frost: March 6 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
16-Day Forecast — Lake San Marcos
- Sun77°65°0%
- Mon77°62°1%
- Tue80°59°0%
- Wed84°59°0%
- Thu84°61°0%
- Fri85°60°0%
- Sat80°63°1%
- Sun88°62°3%
- Mon86°62°11%
- Tue87°67°11%
- Wed90°69°5%
- Thu93°72°13%
- Fri92°71°19%
- Sat86°68°15%
- Sun89°68°14%
- Mon91°65°13%
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.
ZIP codes in Lake San Marcos
- 92078