Plan your visit
When to visit
Mediterranean climate, ~287 sunny days a year, and essentially all of the rain between November and March. The planning question isn’t “will it be nice” — it’s “what do you want running, blooming, or snow-capped.”
March – May
The sweet spot
Etiwanda Falls still flowing, wildflowers on the preserve, snow lingering on the peaks, and hiking weather all day. The LA County Fair runs in May at the Pomona Fairplex (2026: May 7–31, Thu–Sun). If you can pick your dates, pick these.
June – August
Hot, dry, and built for evenings
Rain-free and reliably 90s-to-triple-digits — August is the hottest month. This is baseball, free-concert, and movie-night season; hike at dawn or not at all, and expect the falls to be running low to dry.
September – November
Warm and clear
Warm days, cooling nights, and after the first Santa Ana winds, the clearest mountain views of the year. Watch for wind- and fire-related trail closures — check alert pages the morning of any hike.
December – February
Mild, green, best waterfall odds
Nearly all of the year's ~18 inches of rain lands now, which means green foothills and the strongest flow at Etiwanda Falls. Snow sits 40 minutes away at Mt. Baldy. Bring a layer; evenings drop into the 40s.