After a recent surge of warmer weather, temperatures have returned to closer to normal for San Francisco this week.
After a high temperature of 86 was recorded on May 1 at San Francisco International Airport, highs this week will stay in the low to mid-60s.
Temperatures will recover to near seasonable by Wednesday with partly sunny skies.
Thursday will be partly sunny with cloudy conditions. However, in the evening, it will become cloudy with a couple of showers early in the evening.
Looking ahead to the weekend, conditions stay the same with highs reaching the upper 60s Saturday and mostly sunny skies.
Overnight lows through Friday will stay in the 50s.
Warmer air will build from California to Washington into Tuesday raising temperatures to near-record levels.
Waves of arctic air invading the eastern half of the United States this week will culminate with the coldest weather of the season so far for some areas by the second weekend of February.
The new week will bring more opportunities for snow to create slick travel in the northeastern United States, starting with a winter storm set to sideswipe New England on Monday.
As the first of several waves of arctic air sweep southeastward across the Midwest, just enough snow will occur to cause slippery travel over a broad area into Monday.
Cold and snow showers are in store for the New Hampshire primary on Tuesday but should not significantly impact voter turnout.
In some circumstances climate, environmental factors and weather have led to some of the most exciting, mysterious and academically important discoveries of all time.