May shatters precipitation averages, sets record for Rexburg

2 min


This is a guest post from local weather enthusiast Lee Warnick. 


Precipitation: 3.64 / 206 percent of average

Snowfall: 0.0 / 0.6 inches average

2018 annual precipitation (5 of 12 months): 9.83 / 172 percent of average

2017-18 water year precipitation (8 of 12 months): 11.93 / 134 percent of average

2017-18 season snowfall: 49.3 / 84 percent of average

We need only 0.63 inches, or 17 percent of normal, in the final 4 months to clinch an above average water year. And we received almost half this amount on June 1!

Let’s get right to the green superlatives:

  • 5th wettest May in 47 years and the wettest May since 1995.
  • 9th wettest month all time and the wettest overall since August 2014.
  • May 23, with 1.30 inches, was the wettest May day ever, breaking the previous record of 1.10 inches from May 9, 1991.
  • May 23 was also the 6th wettest day of all time and the wettest overall since June 10, 2004 (1.43 inches, also the all-time daily record).
  • We’ve now had three straight months with 2-plus inches of precipitation (2.20 in March and 2.60 in April). This has happened only one other time — a 4-month run from September through December 1983, part of the really wet and super-snowy early-mid ’80s.

May actually started on the dry side. After receiving 0.18 inch on the 1st, we saw no more precip until the 10th. But from then on, at least a trace of precip was recorded on 18 of the month’s 22 remaining days, including two streaks of 4 and one of 5 straight days.

In considering these statistics and records, please keep in mind that the official airport recording station was on the blink on two of our wettest days, and I had to use estimated data from my and other nearby Personal Weather Stations to fill in the gaps.


High temperatures: 69.2 / 3.1 degrees above normal

Low temperatures: 43.2 / 4.5 degrees above normal

Highest temperature: 81 on the 25th

Lowest temperature: 31 on the 2nd

Lowest wind chill: 30 on the 1st

We had the mildest average May minimum temperatures on record, breaking the previous mark of 42.6 from 1994

In addition to the all-time mildest May average minimum temperatures, May’s average high temps were the 10th warmest in 47 years and the warmest since 2009. This seems like an odd combination with all of the rain we received, but even during our wettest periods, high temps were mostly near or above normal, and, of course, all of those clouds held night-time lows well above normal.

Six of the past seven May months have had above normal high temps but this May also broke a two-month run in 2018 with below-normal highs.

Last week’s tornado warning

Now, two clarifications to my post about the twin-Tornado-Warning Thursday:

Upon a closer look, I erred in reporting six tornadoes. There were six separate reports of a tornado (now increased to eight in the daily report, though one seems to be a duplicate), and some of them likely were spotting the same tornado.

In looking at the locations and times of the reports on a map I created, I’m guessing the national tornado referees will end up putting three different tornadoes in the official records, not six. Rookie mistake, but hey, we don’t get much tornado experience ’round these parts!

I was at the Treehouse Nursery in Hibbard Saturday afternoon and noticed plenty of hail damage there and in the surrounding area northwest and north of Rexburg, including ready-to-cut alfalfa fields that had been pummeled. This was from the tornado-spawning No. 3 late afternoon storm. And Scott Galer sent me a video clip he had seen on social media showing large trees felled by the early afternoon storm (No. 1) near Moody, east of town.

I’m afraid I must have come across as oblivious or insensitive when I wrote that we escaped harm from these two storms by maybe five miles each time. Many of my readers live or farm in areas to the east, west or north who were impacted by one of these Thursday storms, and I hope you will excuse my big city tunnel vision.