Weather and climate in Arroyo Grande, CA
What the weather is like in Arroyo Grande
The warmest month in Arroyo Grande is August, with average highs of 75°F. The coolest is February, when nights average 47°F. About 15.7 in of rain and snow falls in a typical year, most in January and least in August.
Skies are clearest in August (18% average cloud cover) and cloudiest in December (48%). Combining cloud with the length of truly dark nights, October, September, November offer the most clear, dark hours for stargazing.
Clear, dark hours per night
Hours of full astronomical darkness in mid-month, multiplied by the average share of clear sky. A rough guide to how much good observing time a typical night offers.
Monthly averages
| Month | High | Low | Precipitation | Cloud cover | Humidity | Wind | Dark hours |
|---|---|---|---|---|---|---|---|
| January | 59°F | 47°F | 3.1 in | 47% | 74% | 7 mph | 11.0 h |
| February | 59°F | 47°F | 2.7 in | 45% | 76% | 7 mph | 10.2 h |
| March | 61°F | 48°F | 2.4 in | 42% | 77% | 7 mph | 9.2 h |
| April | 63°F | 49°F | 1.1 in | 35% | 75% | 8 mph | 7.9 h |
| May | 67°F | 51°F | 0.6 in | 27% | 71% | 7 mph | 6.7 h |
| June | 71°F | 54°F | 0.2 in | 18% | 67% | 7 mph | 5.9 h |
| July | 74°F | 58°F | 0.1 in | 19% | 65% | 6 mph | 6.3 h |
| August | 75°F | 58°F | 0.1 in | 18% | 66% | 6 mph | 7.5 h |
| September | 75°F | 58°F | 0.2 in | 18% | 64% | 6 mph | 8.8 h |
| October | 71°F | 55°F | 0.9 in | 26% | 65% | 6 mph | 9.9 h |
| November | 65°F | 51°F | 1.3 in | 36% | 69% | 6 mph | 10.8 h |
| December | 59°F | 47°F | 2.9 in | 48% | 73% | 7 mph | 11.2 h |
Climate nearby
Climate averages: NASA POWER, 2001–2025, for the grid area around 35.00, -120.63 (about 50 km across). High and low temperatures are estimated from the monthly mean and the average daily range. Hills, coasts and cities can differ from the area average. Sources and methods.