Weather in Riverside in January

Prime time. If you get to pick your dates, January is the one. Highs average 20.4 °C, lows 7.9 °C, and rain falls on 5 days — nothing in the month is working against you.

January ranks 4 of 12 in Riverside: past the worst of the year but short of April, which is the month to book if the dates are open.

Rain falls on only 5 days, so an itinerary with no wet-weather fallback is a reasonable risk. Nothing specialised needed — this is the month you pack for the trip rather than for the weather.

What the averages hide

Averages flatten a month, and this one hides a few things: it never really gets hot: not one day in an average January reaches 30 °C. Across the twenty years measured, the hottest January day reached 32.5 °C and the coldest night fell to -1.9 °C, and the wettest single day dropped 63 mm — roughly 109% of the month's rain in one day.

This is the volatile part. January rainfall has ranged from 2 mm to 200 mm across the twenty years measured — a 198 mm spread around an average of 58 mm. The average is real but almost no individual January looks like it, so treat the figure as the middle of a wide range rather than a forecast.

Wind is light at 6.7 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 55%.

How January sits in the year

Temperatures hold steady either side: 19.8 °C in December, 20.4 here, 20.8 in February. Nothing about the timing within the month matters much.

Daylight in January

January sits at the dark end of Riverside's year — 10.1 hours of daylight against 14.4 at midsummer, gaining 0.5 hours across the month. Sightseeing days are genuinely shorter, and an itinerary built for summer will not fit.

An inland climate

With no coast nearby, the year swings a fair way — 29.5 °C between the warmest afternoons and the coldest nights, wider than any coastal city at this latitude would manage.

How busy it gets

Peak season. Expect the highest prices of the year and to be booking well ahead.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

January in Riverside versus nearby

If Riverside is one option among several, the nearby comparison is worth making. Irvine is close enough to be a coin toss — 2.8 °C cooler, the same number of rain days. Los Angeles is close enough to be a coin toss — within a degree on temperature, the same number of rain days.

So: January is effectively as good as it gets here — 5 points behind April, which is inside the margin where the weather stops being the deciding factor and price starts being it.

Every month in Riverside

See all twelve months in Riverside, or where else to go in January.