Solar cycle vs Utah precipitation

 As I have suspected for many years there is a link between the 11-year solar cycle and the amount of precipitation that falls in Utah. I first suspected a link after looking at Utah Lake levels and noticing the lake tends to peak two years after the solar minimum.

I compared the Utah Snow Water Equivalent (SWE) from 1981 to 2025 looking at the three year period that includes the solar max/min year, if the Utah SWE was near average I did not compare those years. In this comparison I found a correlation in 17 of 20 (85%) years. I then compared the Utah Water Year (WY) from 1981 to 2025 looking at the three year period that includes the solar max/min year, if the Utah WY was near average I did not compare those years. In this comparison I found a correlation in 18 of 21 (86%) years. I also looked at Alta UDOT guard data and past Utah Lake levels and noticed some nice correlation with the 11-year solar cycle as well but not as strong.

Conclusion:  Utah has a strong correlation to the 11-year solar cycle and an increased chance of above normal precipitation surrounding the solar minimum years and an increased chance of below normal precipitation surrounding the solar maximum years. There are obviously other factors in play, the solar max/min years don't guarantee a dry/wet year but do increases the odds by as much as 80%. Click HERE for a link to the Google sheet with the data, most compelling data is the Utah tab which looks at the entire states snow/water from the snotel sites and should be the default page.

*For those wondering why there is a correlation, my theory (based on reading articles by those smarter than me) is partly because the amount of cloud formation is linked to cosmic rays. The earth's magnetic field is influenced by solar activity, the more solar activity the stronger the earth's magnetic field and the less cosmic rays reaching the earth's atmosphere. Cosmic rays ionize the atmosphere which provides condensation nuclei for water droplets to condense on, more cosmic rays equals more clouds and the potential for more rain/snow to fall.

The Utah snow water equivalent is down to 57% of normal.

 

The Utah Snow Water Equivalent is 61% of normal.

 

The Utah Snow Water Equivalent Map.

 

Record rain for Salt Lake City!

The Salt Lake City airport recorded it's 2nd wettest day in history on October 4th 2025 with 2.47" (2.61" storm total)! This is the most 1-day rain ever recorded at the airport location because the instrumentation in 1901 was in downtown SLC. Storm total of 3.74" in Stansbury Park from the same storm.

Here we go again!

Here we go again with more record heat for the official Salt Lake City airport (KSLC) observation location. Salt Lake City is setting record heat at a much faster rate than other locations in Utah for the reasons below.

The current airport location has undergone significant changes in ground cover since it was installed in 2010. In June 2010 (see below image) it was a grassy/weedy area with less pavement/buildings around, the observation site now (May 2025) is surrounded by dirt/gravel with more buildings/pavement encroaching on the site. Nothing can be done to eliminate the large scale urban heat island effect which is one reason for the warmer temperatures. The second reason for the warming temperatures is the change in ground cover directly under and around KSLC which something could be done about. The native vegetation could be restored directly under and around the site or the site could be moved 0.25 miles to the south where native vegetation still exists.

For how 2 meter temperatures are affected by ground cover check out this article https://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S0187-62362008000200002 that includes a comparison (article 3.2) of the 2 meter air temperatures on 15 calm, sunny, dry days. The study looked at the air temperature difference over three different surface types including asphalt/concrete, soil, & grass. This study can directly relate to what is going on at KSLC on sunny light wind days with the change in ground cover directly under and around the station changing from a weedy/grassy area to dirt/gravel area.

*Of note is the official observation site was located in downtown Salt Lake City until 1928 before being moved to the airport. The airport location was then moved in 2010 to the current location in the image above.

The Utah Snow Water Equivalent is 94% of Normal.

 

Utah Snow Water Equivalent is 85% of normal.

 

Snow Cover

 

Utah Snow Water Equivalent is 75% of Normal