So far, the month of May has been cool, wet and cloudy. Through Tuesday, May is averaging 2.8° cooler than average. Every month so far this year has been cooler than average. We’ve had 13 days this month that have been cooler than average, 7 warmer than average and 1 exactly average. The warmest so far has been 78° on the 18th. We’re still waiting for our first 80-degree day of the year (average first 80° is April 30.
Rainfall has totaled 3.56″ and that’s 0.88″ above average-to-date. We’ve only had five days this month with no rain in G.R. For the year, Grand Rapids has had 16.17″ of precipitation and that’s 3.89″ above average. We’ve only had two days when we have seen lightning or heard thunder in G.R.
Picture Tue. from the S. Haven Lighthouse. This has been an unusually cloudy month. We’ve had just 34% sunshine this month, compared to 56% in an average May. 15 of 21 days have had 30% sunshine or less. The cloudy cool pattern has kept the lakes chilly. Tue. evening the water temp. at the Port Sheldon buoy was 46.9 and at the mid-Lake Michigan buoy, the water temp. was just 39.2°.
The latest 8-14 Day Outlook from the Climate Prediction Center for May 29 to June 4 continues the trend of cooler than average temperatures in Michigan.
The warmest summer we’ve ever had in G.R. was 1921 with an average temp. of 74.6°. The coolest was 1992 with an average temp. of 65.5°. That’s an average of all the high and low temperatures for the months of June, July and August.