Weather in Irvine in January

Prime time. If you get to pick your dates, January is the one. Highs average 17.6 °C, lows 13 °C, and rain falls on 5 days — nothing in the month is working against you.

January ranks 9 of 12 in Irvine: past the worst of the year but short of June, 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. Pack for 17.6 °C days and 13 °C nights; the spread matters more here than any single number.

What the averages hide

Averages flatten a month, and this one hides a few things: the day barely swings — 4.5 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest January day reached 26.9 °C and the coldest night fell to 6.4 °C, and the wettest single day dropped 73 mm — roughly 107% of the month's rain in one day.

This is the volatile part. January rainfall has ranged from 1 mm to 226 mm across the twenty years measured — a 225 mm spread around an average of 68 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 9.6 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 68%.

How January sits in the year

Temperatures hold steady either side: 17.5 °C in December, 17.6 here, 17 in February. Nothing about the timing within the month matters much.

Daylight in January

January sits at the dark end of Irvine'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

Despite being inland, the year stays fairly even: 10.7 °C between the year's warmest afternoons and coldest nights.

How busy it gets

Quiet. Few other visitors, cheaper rooms, and a real chance some seasonal operators are shut.

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

January in Irvine versus nearby

If Irvine is one option among several, the nearby comparison is worth making. Riverside is close enough to be a coin toss — 2.8 °C warmer, the same number of rain days. Los Angeles is close enough to be a coin toss — 2.6 °C warmer, the same number of rain days.

So: January works, with June the better month by 18 points if the dates can move. If they cannot, nothing here should stop you booking.

Every month in Irvine

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