Los Angeles sprawls across a coastal basin and surrounding valleys in Southern California, between the Pacific Ocean and mountain ranges, at approximately 34.05°N, 118.24°W. It has a climate on the border of Mediterranean and semi-arid (Köppen Csa/BSh) — warm and dry — with a mild, wet winter and a long, dry summer, and it is famous for its many microclimates, with coast, basin, valleys and hills differing sharply on the same day.

Summer, from May to October, is warm, sunny and essentially rainless, with August and September the warmest — coastal highs around 24–27°C but inland valleys often 10–15°C hotter. The coast is cooled by sea breezes and by the morning marine layer of low cloud and fog known locally as 'June Gloom', while heat waves — sometimes driven by hot, dry Santa Ana winds — can push inland temperatures past 38°C. Rain in summer is almost unheard of.

Winter, from December to March, is mild and the wet season, with the coolest months bringing coastal highs around 19–20°C and mild nights, rarely near freezing on the coast. Most of the year's rain arrives in this season from Pacific storms, sometimes as intense atmospheric-river downpours that cause flooding and mudslides, especially on hillsides bared by wildfire. Between storms, though, winter days are frequently sunny and pleasant.

Los Angeles is dry, receiving only around 350–380 mm of rain a year on average, over 90% of it falling between November and April, while summer is effectively rainless; totals swing enormously from year to year with the El Niño cycle. Live rainfall, humidity, and pressure readings for the city are shown in the panels above.

Two features define Los Angeles's weather: its patchwork of microclimates, where the beach can be cool and foggy while the valleys bake, and the Santa Ana winds — hot, dry gusts that blow from the desert toward the coast, most often in autumn, driving up temperatures, plunging humidity and dramatically raising the risk of the wildfires that are a recurring hazard across the region.

To follow any single measurement in Los Angeles more closely, use our live instruments: the online barometer for atmospheric pressure, the thermometer for temperature, the hygrometer for humidity, the anemometer for wind speed, the wind vane for wind direction, and the rain gauge for rainfall.