Quote:
Originally Posted by ChiSoxRox
Another unusual aspect of the coastal California climate is having one of the strongest seasonal lags on the planet:
Here in Fairbanks, we have a very short seasonal lag, with the warmest average highs being the first week of July, so our weather is already trending cooler with fall (leaves changing, cold rains, potential for frosts) arriving in mid-August. |
Map really shows nicely how in most years the warmest period on most of the Pacific coastal fringe is in mid/late August into September, later than most of the rest of the country, where heat peaks in late June, July, early August (July peak heat covers most of the map). The current heat wave in the northwest is somewhat unusual in being early, before August. Portland OR, being inland from the coast, does have a July heat peak though. But most of the San Diego, L.A. and San Francisco metro coastal areas don't have peak heat until after mid August.
In parts of Arizona, New Mexico, and west Texas peak heat occurs in late June. This is because the monsoonal moisture usually hasn't arrived yet from the Gulf, so the early summer sun (when it is highest in the sky at noon) beats down brutally on the desert. By mid July, the monsoonal clouds and rain have usually arrived (some years they don't), cooling things off a bit.