Tule Fog Season Arrives as Fresno Cools: 73 Tuesday, Then Down Into the 60s
The week's forecast cools steadily — Tuesday 73/46, Wednesday 71/45, Thursday 68/44 — and November marks the start of tule fog season on Fresno County roads.
Fresno's forecast this week tells the season's story in three lines: Tuesday reaches 73 with a low of 46, Wednesday cools to 71 and 45, and Thursday tops out at 68 with a low of 44. The trend is gentle, dry and unmistakably autumnal, trading the valley's long summer for mornings that require a jacket and afternoons that do not. For a city that measures its year in extremes, this is Fresno at its most moderate.
November also opens the other season valley residents plan around: tule fog. The dense ground fog forms on calm, clear nights as the moist valley floor radiates its heat away, and it can reduce highway visibility to a few car lengths by morning, especially in low ground near the San Joaquin River and along SR-99, SR-41 and the county's rural roads. It often burns off by late morning, which is why it disrupts commutes and school start times more than whole days.
Fog driving in the valley follows hard-earned rules. Slow down well below the speed your instincts suggest, use low-beam headlights, leave far more following distance than usual, and never stop in a travel lane. If your trip can wait for the burn-off, waiting is the safest option of all. Fresno drivers with long memories treat November fog with respect, because the season's chain-reaction crashes have taught the valley the cost of treating fog like ordinary weather.
The cooling trend behind the fog is otherwise good news. Daytime highs in the upper 60s and low 70s are ideal for the city's parks, the San Joaquin River Parkway trails, Chaffee Zoo and the Tower District's patios. Overnight lows in the mid-40s are cold enough to matter for exposed pipes in outlying areas only in deeper cold snaps, but gardeners will note the direction: the growing season is winding down across Fresno County.
Enjoy the mild afternoons, and respect the gray mornings. That pairing, pleasant days and foggy dawns, is the valley's November signature, and this week's forecast delivers both right on schedule.