From mild 'El Nino' to a wet 'La Nina'
Here's a month-by-month review of 2010's weather, which continued the recent trend of "wide weather extremes."
January
Thanks to the warm 'El Nino' sea-surface temperature event in the tepid waters of the Pacific Ocean, last January was the second warmest January on record dating back to at least 1895, the inception of local Coeur d'Alene weather record-keeping.
The average maximum reading was a very mild 39 degrees. We hit 50 degrees on Jan. 18, Martin Luther King Day. Our average minimum temperature was 28 degrees. That gave us a monthly mean reading of 33.5 degrees, second only to the 33.7 degrees set back in January of 1953. The coldest reading last January was 11 degrees on the 8th.
While our precipitation (liquid) was near normal at 3.10 inches, our snowfall last January was a puny 2.4 inches. Only January of 1944, during World War II, had less total snowfall at a scant 1.4 inches. Our normal January snowfall since 1895 has been 21.2 inches. Our all-time record January snowfall was 82.4 inches in 1969.
February
Once again, thanks to the warm El Nino, last February was very mild with an average high of 45 degrees and a low of 30 degrees for a monthly mean temperature of 37.5 degrees, the sixth mildest February on record. The mercury hit 58 degrees on Feb. 27. The month's coldest reading was 18 degrees on Feb. 21.
The 0.3 inches of snow in February 2010 was the second least on record to the 0.2 inches gauged in 2005. The month's total precipitation (liquid) was 1.98 inches, a bit below the normal since 1895 of 2.14 inches.
March was also warmer than normal with an average (mean) temperature of 42 degrees, four degrees above normal.
We only measured a 'trace' of snow during the entire 31-day period in town, which tied the record for least March snowfall since 1895 with five other years.
The total Jan. 1 through March 31 snowfall was a paltry 2.7 inches in Coeur d'Alene, the least snowfall ever for the 90-day period. Total precipitation was 2.01 inches in March of 2010, a bit above the 1.99 average since 1895.
April turned a bit cooler with a monthly mean temperature of 46 degrees, one degree below normal, as El Nino weakened in the Pacific Ocean.
The total precipitation last April was 3.21 inches, nearly double the 115-year norm of 1.75 inches since 1895. Nearly half of the month's rainfall was gauged during the last four days of April, 1.57 inches to be exact.
April's snowfall total of 0.6 inches was near-normal and brought the final meager 2009-10 seasonal snowfall total up to 18.4 inches, the ninth least on record since 1895. Ironically, the 0.6 inches last April was exactly double the 0.3 inches combined February and March snowfall totals.
As the El Nino fell apart in the Pacific Ocean waters, May turned out to be a very cool and wet month across the region. Our total precipitation was 3.16 inches, nearly a full inch above the 115-year normal since 1895 of 2.21 inches. There were 'traces' of snow observed on May 6 and 8.
Our average maximum reading last May was 61 degrees. Our average low temperature of 39 degrees gave us a monthly mean of 50 degrees, two degrees below normal. The 52 degrees on May 29 was a record low maximum for the date. The frosty 26 degrees on May 5 was the month's coldest temperature and set a new record low for the date. The 30-degree low on May 24 tied the record set in 1950. The month's warmest temperature was 82 degrees on May 17 during a very brief mild spell.
June 2010 was the second wettest month of June on record since 1895 in Coeur d'Alene. We measured a whopping 4.63 inches during the 30-day span, 2.85 inches above normal. Only June of 1947 was wetter with 5.09 inches of total precipitation.
With an average high of just 69 degrees and an average low of 48 degrees, it gave us a chilly mean of 58.5 degrees, exactly three degrees below normal. The day's high of only 49 degrees on June 16 was a new record low maximum reading for the date. The month's highest reading was 88 degrees on the 28th. The lowest temperature was 40 degrees on June 6.
July turned drier and warmer with only 0.70 inches of total precipitation compared with the 115-year normal since 1895 in Coeur d'Alene of 0.96 inches.
There were seven 'Sholeh Days' above 90 degrees. The month's high was 95 degrees on July 26. The coolest reading in July of 2010 was 43 degrees on the 1st. The average high was 82 degrees and the average low was 53 degrees, both near normal. The mean temperature was a normal 67.5 degrees.
August
Ironically, August had exactly the same average high as July at 82 degrees and the identical low reading at 53 degrees, again close to the 115-year norms for August. The month's warmest afternoon was 96 degrees on the 17th, which was the summer of 2010's hottest day. The month's lowest temperature was 39 degrees on Aug. 30, a near-record low for the date.
Rainfall was about half of the August normal at just 0.68 inches. There were growing worries about wildfires shortly before the annual North Idaho Fair and Rodeo, which was GREAT!
September
September was another warm and dry month with more threats of wildfires across the region, especially during the hot, dry and windy first half of the 30-day period, when area temperatures were close to 90 degrees. The month's low was 40 degrees on the 2nd.
We finally saw some much-needed rains develop between Sept. 16-19, when 0.63 inches of precipitation substantially lessened the fire danger threat. Our monthly rainfall total of 0.90 inches, however, was 0.68 inches below the normal September precipitation since 1895 of 1.58 inches.
October
October saw a big increase in precipitation thanks to the new 'La Nina' sea-surface temperature event building in the waters of the Pacific Ocean. The 3.23 inches of rainfall was 1.30 inches above the normal of 1.93 inches since 1895.
The month's warmest afternoon was the 83 degree reading on the 2nd. The coolest morning was a frosty 29 degrees on Oct. 17. But, there were no widespread killer-type freezes in October 2010. Our gardens thrived.
November
As the chilly and wet 'La Nina' kicked into high gear during the second half of November, we began seeing much colder temperatures and greatly increased amounts of precipitation across the region, almost on a daily basis.
Temperatures dipped to record lows near -10 degrees on Nov. 23 and 24, just ahead of the busy Thanksgiving weekend. Our maximum readings at near 10 degrees above zero both days were likewise new record lows for Nov. 23 and 24.
Between Nov. 18 and Nov. 30, we gauged an all-time November snowfall total of 38.3 inches, easily surpassing the 31.6 inches measured during November of 1973. The 38.3 inches was nearly 20 inches more than the 18.4 inches of snow that we received all last winter in 2009-10 during the warm 'El Nino' sea-surface temperature phenomenon, one 'EXTREME' weatherwise to the other.
The total liquid precipitation for November 2010 in town was 5.81 inches, nearly double the 2.97 inches that we normally receive. We certainly needed the added moisture, and we got it in spades.
December
Until Old Man Winter returned with a vengeance during the last week of the month, December 2010 was unusually mild with far less rain and snow than normal.
The major 'thaw' that occurred from Dec. 8-14 took all of the 20-inch snowpack that we had on the ground following the snowiest November since at least 1895 with a whopping 38.3 inches, nearly 20 inches more snow than we received all last winter during El Nino. The rapid melting sent Lake Coeur d'Alene's water level to its highest reading in December since 1995.
The month's warmest temperature on Player Drive was 47 degrees on Dec. 12. There were six afternoons this December above 40 degrees, unusual indeed for a 'La Nina' event.
But, between Dec. 28 and 30, we received another 14.7 inches of snow that pushed our monthly total to an above normal 24.2 inches, which included Dec. 29th's daily record snowfall of 12.1 inches that broke the previous mark for the date of 10 inches in 1954.
Our monthly precipitation (liquid) total stood at 3.74 inches, just below the normal of 3.92 inches since 1895 as of 10 a.m. on Thursday. Our annual precipitation total since Jan. 1 was 33.15 inches, a whopping 7.04 inches above the 26.11 inches that we normally receive in a calendar year dating back to 1895. No precipitation was expected on Dec. 31.
We're expecting that Friday, Dec. 31 will be the coldest morning of the month at just below the zero mark.
All in all, it was another month of Wide Weather 'EXTREMES,' as was the entire year of 2010.
2010 weather stats:
Highest Temperature: 96 degrees on August 17.
Coldest Temperature: A record -9 degrees on November 24.
Total Liquid Precipitation: 33.15 inches (normal 26.11 inches).
Total Year's Snowfall: 65.8 inches (normal 66.7 inches).
(62.5 inches in November and December)
uSpecial note: I'm raising my 2010-11 projected seasonal snowfall total to 92.4 inches, up from my October prediction of 81.3 inches. I'll have more details next week.
Cliff Harris is a climatologist who writes a weekly column for The Press. His opinions are his own. E-mail him at sfharris@roadrunner.com.