The warm sunshine that arrived in the Inland Northwest over the weekend has made early spring 2013 the warmest since 2007.
Forecasters are calling for temperatures to stay in the 60s through Thursday and possibly Friday.
A seven- to eight-day run of temperatures in the 60s or lower 70s would be the longest string of early mild weather since 2004.
On Monday, the high at Spokane International Airport was 70 degrees.
A year ago, Spokane residents woke up to a trace of snow on April 5.
Families flocked to Riverfront Park on Monday as schools’ spring break coincided with the warm-up.
An analysis of weather data shows that the warmest early spring on record was in 2004, when the temperature rose to 60 degrees or more on 18 days during the period from St. Patrick’s Day to federal tax day on April 15, said Ron Miller, a forecaster with the National Weather Service.
The record high for Monday was 77 in 1900. The record low was 14 in 1936, a statistic that shows the wide variability of early spring weather.
That variability can be influenced by global weather phenomenon such as La Niña and El Niño, among others, experts said.
“Those variables in climate play a role in whether our spring season starts out warmer,” weather service forecaster Steven Van Horn said.
In 2012, Spokane saw one day in late March and five days in early April with highs of 60 degrees or warmer.
In 2011, there were no early spring days that broke 60 degrees and only one in 2010.
In 2007, the region saw two brief warm-ups of four days each in March and early April.
The last time Spokane saw a high of 70 degrees or warmer was last Oct. 11, when the temperature reached 71.
The mild weather should moderate through the week. A low-pressure system is going to graze the region today and could bring a slight chance of thunderstorms to mountain areas north of Spokane and Coeur d’Alene.
Mostly sunny skies are forecast for Spokane today and Wednesday, with a high of 67 today and 64 on Wednesday.
Lows should be in the upper 30s to lower 40s.
Clouds and a chance of showers return starting later Thursday and continuing Friday, with highs still in the 60s.
The weekend will likely be cooler, with highs around 55 and chances of showers on both days, forecasters said.