Lows reached freezing for many areas in Northern Nevada Tuesday morning. Wednesday morning will be slightly warmer.
The calendar says fall, and so does the thermometer. Tuesday was the coldest start Northern Nevada has seen in months. For the first time this season, Reno reached freezing at the airport, with many surrounding areas in the 20s. Reno usually sees its first freeze on October 19. This is according to the 30-year average from 1991-2020. Wednesday morning will be a touch warmer by a few degrees, but it will still be cold enough for coats and pumpkin spice. Lows around Lake Tahoe will be in the 20s. Yikes! Truckee made it down to 16 degrees Tuesday morning and will be in the 20s Wednesday morning.
Tuesday morning would have been even colder if we had cleared out sooner. We had some clouds around Reno between 2 and 3:30 a.m. Tuesday, which may have prevented temperatures from dropping even further. Radiational cooling occurs when skies are clear and winds are light, allowing the warm air we gathered during the day to escape rapidly back into the atmosphere. We also had a large upper-level low over Nevada Tuesday morning, which can be thought of as a cold pocket of air. The low is moving east, and high pressure is moving back in, allowing warmer air to build in as well. Great hiking weather indeed.
Wednesday morning will still be cold as skies stay clear and winds stay light, but with the low moving out of here, temperatures will be slightly warmer on Wednesday. Still cold enough for a coat, though. Wednesday afternoon will be awesome, with highs in the lower 70s. In fact, it will be an awesome week overall, as temperatures stay near average through at least Friday. It will be slightly above average over the weekend.
Reno usually sees its first freeze on October 19, and looking back at climate numbers from 1996-2026, Reno saw three days when the first freeze occurred in November, 17 days from October 16-31, and 11 days before October 16, including the 13th. Keep in mind the airport is usually the warmest spot. There wasn’t any frost Tuesday morning because the temperature has to reach the dew point for that to happen, and dew points were way too low.
The three coldest mornings of the season so far occurred this week, on Sunday, Monday and Tuesday. We also had some mornings in the 40s in September.
