Palm Springs weather in September

Forum posters generally plan on daytime highs around 90F in September, though a heat wave can push conditions to 100F or more, with nights cooling to a comfortable 65F. Posters note the park's northern reaches near Twentynine Palms sit at higher elevation and run noticeably cooler than the lower desert (about 10F cooler than nearby Palm Springs), which matters when picking which trails to tackle on a hot day. A near-constant breeze is repeatedly credited with making the heat more bearable, and brief, short-lived thunderstorms are a real possibility this time of year. Standard ranger advice for September hiking: start at sunrise and be done by mid-morning, and bring significantly more water and electrolyte drinks than instinct suggests.

Forum posters describe May in Palm Springs as genuinely hot, with highs commonly in the upper 90sF especially later in the month - one May visitor reported highs in the upper 90s to low 100sF most days, along with warm overnight temperatures and occasional poor air quality from blowing dust and sand. Posters consistently recommend early May specifically over late May for anyone prioritizing pool time without triple-digit heat, describing that window as warm enough to swim in an unheated pool while still falling short of the true 100+F heat typical from June through September. Posters consistently flag May, alongside late October, as a genuine shoulder-season sweet spot for avoiding peak winter rates while still getting comfortable outdoor conditions, at least early in the month. Posters generally recommend planning outdoor time for morning or evening once temperatures climb later in May.

November is the desert at its best, and the forum's own window is roughly 15 October to 1 December: days around 24°C, nights dropping to about 12. Two things they raise that the temperature cannot. First, light — the sun goes behind the mountains close to 4pm and it is dark by about 5 by mid-month, which shortens an afternoon far more than the date suggests. Second, timing inside the month: the end of November fills up with snowbirds arriving and Thanksgiving. Pools swim fine on a sunny day if heated; unheated ones really do not. Rain is rare, though storms do pass through.