Long Beach • Statistics for May

May: Summer Onshores Take Over

May is when summer's onshore regime starts to take over Long Beach. Average swell height slides to 4.9ft (1.5m) and period eases to 11.7s, still long-period but much less powerful than winter. The swell direction window remains excellent - WSW (34.7%) and W (31.6%) dominate, and the SW-to-WNW quadrant supplies over 88% of the total wave energy. However, the wind rose flips: offshore NE to ESE winds account for only about 11% of the observations, while onshore WNW winds blow in at 31% and NW adds another 10.3%. Ideal wind scores drop to just 20%, so many days are small and bumpy. Water temp climbs to 12.0°C and air temps average 10.5°C, with precipitation down to 2.71mm/day - the classic setup for summer sea breezes. Still, because the swell is almost always from a good direction, even a 3-4ft (0.9-1.2m) WNW swell can be fun if you find a dawn patrol window before the wind clocks onshore.