Wednesday is warmest day so far this year, cool-down ahead

Posted: Updated:

PHOENIX -- Today could be our warmest day of the year so far with Valley temperatures forecast to top out near the 90-degree mark this afternoon.

Based on the last 25 years of data, Phoenix typically sees its first 90 on March 30. If you look at data going back to 1896, the average is April 4. The date has been slowly moving up in the year, likely because of the urbanization of Phoenix and warmer overnight lows.

While it is a bit early, hitting 90 today would not be a record-breaker for the earliest 90-degree date.

The earliest we've seen 90 degrees was February 24, 1904, and again in 1986, according to the National Weather Service. The latest was May 12, 1912.

It looks like our late-winter warmth won't last long. A Pacific storm system is heading our way, bringing cooler weather for the weekend.

Temperatures should drop back to the low 80s on Saturday, and the mid 70s by Sunday as the storm approaches.

Forecast models show a 30 percent chance of rain in the Valley on Monday, with snow likely in the high country Monday and Tuesday. Valley highs will drop back to only 70 degrees on Monday, which by the way, is the first full day of spring. The vernal equinox is late Sunday.