Sandy Utah Weather Blog 2021
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Calendar Year 2021 Climatological Summary




Temperatures ranged from 102.3F on July 7 to 11.8F on December 18. Precipitation was good at 20.06" with October having the highest amount with 4.44". As usual there is not much to say about the wind, as maximum was just 42 mph and the predominate direction was from the southhwest.

December 2021 Climatological Summary

Continuing every other month is wet rhythm, December 2021 was wet. The 15th of the month brought a big snowstorm, dumping 14" (35.6 cm) at my home with 1.21" (3.1 cm) of water content. Six of the past 24 December months have had a day with over 1" (2.5 cm) of precipitation, the largest number of all other months except for July which has 10 such days. The December total was 3.24" (8.2 cm) a goodly amount indeed. That is far above the 24-year average of 1.88" (4.8 cm) during December.

Good precipitation in September, October, and December brought the total for calendar 2021 to 20.06" (51.0 cm). That is just a bit ABOVE the 24-year average of 19.80" (50.3 cm). Drought recovery continues in Utah, but a wet spring is still needed to have an abundant water supply for next summer.

The average temperature was 33.4 F ( 0.7 C) which is dramatically warmer that the 24-year average of 29.5 F (-1.4 C). Just three days had a low temperature above 32 F (0 C).

November 2021 Climatological Summary

Our drought began in July 2020. During the past 17 months, we have had 17.89" (45.4 cm) of rainfall. The 24-year average (12 months) is 19.70" (50.0 cm). The only months with significantly above normal precipitation were August and October 2021. Those two months totaled 8.78" (22.3 cm) just under 50% of the 17 months total.

Since July 1, 2021 precipitation has been above normal, though the rainfall in September 0.27" (0.7 cm) and November 0.39" (1.0 cm) were well below average. We need a near-average winter season to be able to glide through next summer.

Meanwhile, temperatures continue to show the clear effect of global warming. The average temperature for November 2021 was 42.4 F (5.8 C) versus the 24 year average of 39.9 F (4.4 C). The difference here is 1.4 C. A very high value.

Global warming will drastically reduce the number of significant thermal inversions in the Salt Lake valley thus reducing the need to aggressively address pollution problems during the winter months.

October 2021 Climatological Summary

"Holy Cow Batman that was a lot of water!" Yes, October 2021 was the wettest October ever during the past 24 years at this location. At the official Weather Reporting Station at the Salt Lake International Airport, it was the 4th wettest October in history.

I recorded 4.44" (11.3 cm) of rainfall during October 2021. All of the rain came during four periods:

The wettest month during the past 24 years was 5.79" (14.7 cm) in May of 2011.

The rain was welcome unless it found a way into your house as it did at ours. We discovered that our rooftop drainage control system needs some upgrades for events over 1". One inch (2.54 centimeters) of rainfall over 1 square foot equals 0.68 gallons of water. Spead that over 2,500 square feet of roof and you have 1,700 gallons of water to deal with.

This rainfall clearly filled up the groundwater deficits in most areas. This is an important part of overcoming our present draught. This means that much of all future rain and snowfall this winter will runoff in our reservoirs. The draught is not over yet, however, the rains of August and October 2021 are setting a good tone for the future.

La Nina is again in place for this winter season as it was last winter. This pattern suggests normal to below normal precipitation for Utah, based on the available history for (ENSO - El Nino Southern Oscillation)

The average temperature for the month was 50.0 F (10 C) which is below the 24 year average of 50.7 F (10.4 C). There were no days with the temperature over 80 F (26.6 C) and 5 days with the temperature below 32 F (0 C)

September 2021 Climatological Summary

While the American West Desert Monsoon gave us a significant amount of precipitation in August which helped mitigate the ongoing drought, September precipitation was again well below normal. The month had only 0.27" ( cm). The average for September over the last 24 years is 1.21" ( cm).

Temperatures, as expected in a global warming world, were above the 24-year mean temperature by 2 F. The average temperature was 65.9 F ( C). The minimum temperature was 36.2 F ( C) on the last day of the month. In 24 years there has never been a temperature below freezing.

When I was a senior in high school in 1972, the last two days of September brought 4-6" of heavy wet snow across the Salt Lake Valley. I remember it well because it was homecoming at high school and it was so unbelievable. That's the only time I've seen snow in the Salt Lake City area in November.

August 2021 Climatological Summary

The American West Desert Monsoon was the big news for August.

This flow of moist air from the south generally starts in mid-July and ends in mid-September. August 1st brought the first batch of rain (southern Utah had endured many previous blasts of rain from the monsoon, especially the area around Cedar City). That day I recorded 0.78" ( cm). But that was only the beginning. Multiple days of rain occurred August 17-21). These dates included August 17 0.57" (1.4 cm), August 18 2.03" (5.2 cm), August 19 0.43" (1.1 cm), and August 21 0.45" (1.1 cm).

The heavy rain on August 18 was due to a genuine cold front coming in and forcing much of the moisture in the air from the prior day to be precipitated out. August 18th is a bit early for a true cold front, but I've known for years that it can cool off as early as August 12, 1977 (the swimming party that evening, was disappointingly cold).

The total for the month was 4.34" (11.0 cm). Which blew away the prior record for 24 hours of 2.27" ( 5.8 cm) set in 2014. It was so much that it moved the 24-year average from 0.75" (1.9 cm) to 0.90" (2.3 cm)!

The 2.03" that fell August 18 came close to the all-time record for one day which was 2.40" (6.1 cm) on February 12, 2006.

There were no days where the high exceeded 100 F (37.8 C) this year, which is not unusual as in 24-years there have been only 4 days over 100 F during August. The average temperature of 73.0 F (22.8 C) was 1.5 F over the 24-year average of 71.5 F (21.9 C). August 19th was the coolest day of the month (just after the cold front passed). On that day the low temperature was a chilly 49.8 F (9.9 C).

July 2021 Climatological Summary

Finally some rainfall! My station recorded 0.88" (2.2 cm) for the month. That's above the 24-year average of 0.55" (1.4 cm). On average July is the driest month of the year in this area.

Due to the arrival mid-month of the American West Desert Monsoon (my name), rainfall in parts of southern Utah has been heavy with flooding issues in many Utah cities, particularly Cedar City. The monsoon season generally starts in mid-July and continues through August and sometimes even into September. Last year this monsoon never started, and that was the beginning of the current draught. Hopefully, the monsoon will continue in August with fewer flooding events.

On the temperature side, it was HOT, HOT, HOT! I recorded five days with temperatures over 100 F (37.8 C). The Salt Lake City airport recorded a few more than five. That's the most ever. The mean temperature this year was 81.3 F (27.4 C). That was about 5 degrees Fahrenheit over the prior 23-year average. Five degrees might not sound like a lot, but it is huge! Rocky Mountain Power did not have any outages due to the heavy demand, so kudos to them. California routinely does rolling blackouts to make sure their systems don't crash.

Electricity is fundamental to modern life. Let's hope that as we move forward to a greener energy future we don't move so fast that reliable electrical resources become unreliable.

June 2021 Climatological Summary

The drought continued into its 12th month. The last month with reasonable precipitation was June 2020.

While a couple of days recorded a "trace" of precipitation (a trace requires an area of 2-3 sq. feet to be covered in raindrops) there was only one day that recorded measurable precipitation and that was June 24th with 0.13" (0.3 cm). Dry indeed. In the past 24 years there have been multiple years with no precipitation, while the average precipitation for June is 1.04" (2.6 cm).

Temperatures during June 2021 were "crazy hot". June 13-17 was a true hot spell. I had just one day over 100 F (37.7 C) and that was 101.6 F (38.7 C) on June 15. I've only recorded 2 days in June with a temperature over 100 F (37.7 C) in my 24 year record. The official NOAA weather station at Salt Lake International Airport reported 107 F (41.6 C) that day equaling the hottest day in the history of record-keeping in Salt Lake City. The average temperature was a warm 77.4 F (25.2 C)). Over 24 years the average temperature is 67.8 (19.9 C) which demonstrates how June 2021 was abnormally hot.

Meanwhile, there have been several wildfires in Utah, but none of them really got out of control as most were contained to reasonably small areas. I hope that luck can continue as we move through the rest of this summer.

May 2021 Climatological Summary

As I have been pointing out for months now, precipitation in the Salt Lake City area (and many places west of the Rocky Mountains and south of 42 degrees north latitude) has been far below normal since July 2020. Finally, this month governments took notice of the situation and started to take action. Rather than blame this on Climate Change I'd rather point to the La Nina situation off the coast of equatorial South America which has been in force for more than a year now. La Nina typically causes DRY conditions south of the Utah-Idaho border throughout the West (Utah, Nevada, Southern California, etc. ) The good news is the situation there just turned from La Nina to neutral. If an El Nino pattern develops we should have more normal precipitation. We can't predict when this pattern shifts, but we know how La Nina and El Nino change weather flows in the northern hemisphere across the United States.

May 2021 was another month with subnormal precipitation. At my home, I recorded a total of 0.51" (1.2 cm). More than 50% of that total fell on May 23rd. The 24-year average rainfall for May is 1.87" (4.7 cm), so we received about one-third of normal.

Temperatures were above normal with the mean temperature for May 2021 at 60.5 F (15.8 C). The 24-year average is 56.6 F (13.7 C). The highest temperature for May 2021 was 85.7 F ( 29.8 C). The only thing strange about that was that it occurred on May 6. The record high for the month of May in 24-years was 96.4F ( 35.8 C) in 2006.

April 2021 Climatological Summary

Total precipitation was pretty good at 1.69" (4.3 cm). which is below the 24-year average of 2.39" (6.1 cm). So we lost more ground on making up below normal precipitation since September. The rainy periods were May 5-6, 14-16 and 26-27, with the middle of the month beiing the wettest part.

Generally May goes one of two ways wet and miserable or sunny and nice. My guess for 2021 is "sunny and nice", while wet and mserable would certainly help more with the draught.

The last day of the month featured a high of 84 F ( 28.9 C). The first day over 80 F this year. The mean temperature was 48.4 F (9.1 C) versus a 24-year average of 48.5 F, so almost spot on normal.

You may have noticed that the wind at my home is generally well behaved. I believe it is one of the least windy areas in the Salt Lake Valley. The highest ever wind gust in 24 years is 58 mph (25 m/s meters per second).

March 2021 Climatological Summary

The frequency of storms in March 2021 was quite normal. The amount of precipitation that they left behind was not. This year totaled 1.57" (4.0 cm) versus the 24-year average of 1.94" (4.9 cm), or about 25% below average. April averages 2.42" (6.1 cm) so there is hope for a bigger number next month. The current draught is significant, but perhaps not life-altering so long as April is not a bust. We had a dry fall and this means that the first snowmelt will go into the ground rather than runoff into streams and reservoirs. About half of the March precipitation fell on March 20 0.77" (2.0 cm).

The average temperature was 41.5 F (5.3 C) a bit below the 24-year average of 42.8 F (6.0 C). Neither the highest temperature this March 67.9F (19.9 C) on March 8 nor the lowest temperate of 16.5F (-8.6 C) came close to the records for the month.

February 2021 Climatological Summary

For the first time since June 2020, Sandy received a substantial amount of precipitation 2.23" (5.7 cm). The big storm was on February 17th when a "good old snowstorm" dropped from 12-24" (30- 60 cm) over much of the Salt Lake Valley. Smaller storms on the 3rd, 5th, and 27th added to the solid total for February. While the precipitation was welcomed, it still totalled shy of the 24-year average of 2.66" (6.8 cm).

The average temperature was 34.8 F (1.6 C), which was just 0.2 F (0.1 C) above the 24-year average. The strangest temperature anomaly was that the highest temperature for the month was 58.6 F (14.8 C) which was recorded on Groundhog Day (February 2), while the lowest temperature for the month was 15.9 F (-8.9 C) recorded on February 25. Normally in February, it is warmer and the end of the month rather than at the beginning!

January 2021 Climatological Summary

The Utah drought continued into 2021 with well below-average precipitation. The total was 0.37" (0.93 cm). That's the lowest amount in my 24-year history at this site. Spring is the wettest period of the year in Utah and we will need an above-normal spring to get into a comfortable water storage position. Most of the month's precipitation occurred between January 22-24.

Most January's will see temperatures fall toward 0 F (-17 C), but the low this January was 13.5 F (-10.2 C) on January 11. The mean temperature for the month was 32.8 F ( 0.4 C) versus a 24-year average of 30.4 (-0.9 C).