| January kicked 2010 off on a cold note as low temperatures dropped below zero on 9 of the first 10 days. Temperatures never warmed above zero on the 2nd and 4th. Temperatures warmed for mid month, but cold readings returned by month’s end. Around ½ inch of precipitation fell in January, a bit below the monthly normal. Most of what did fall came on two days, with around ¼ of an inch on the 7th and 23rd. It was warm enough on the 23rd such that what fell was in the form of rain. Snowfall for the month was only 4.2 inches, well below the 11.9 inch normal. There were only 4 days with measurable snow fall, and most of that fell on the 7th with 3.4 inches. January is normally Rochester’s snowiest month of the year. |
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High temperatures in February were relatively consistent and close to normal while low temperatures were more variable. Lows in the single digits above and below zero quickly gave way to teens to 20s for the first week and a half, allowing for a mild start to February. Lows would then fluctuate between below zero readings to mid teens for the rest of the month. Snow was more common in February compared to January with measurable snow falling on 10 days. The 13.9 inch monthly total was almost double the normal, and much of the snow fell in the first half of the month. Amounts were spread out during this time, with 4 days recording an inch or more. The last measureable snow for the 2009-10 snow season would fall on the 23rd, well ahead of the usual occurrence which is the second week of April.
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March of 2010 holds the distinction of being the first March on record without any snowfall. Nary a flurry flew during the month that normally receives 9 inches of snow. As the lack of snow attests to, March was a dry month, with only around an inch of rain falling. March was one of the warmest months of 2010 when compared to its average; over 7 ½ degrees above normal. Its 38.3 degree average temperature made this March the 7th warmest on record for Rochester. The first 70 degree temperatures for 2010 came on the 30th and 31st. The windiest day for 2010 was on the 30th when speeds averaged 24.5 mph.
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April continued the warm trend of the spring season with 83 degrees on April Fool’s Day. These mild conditions would persist throughout the month as only 2 days recorded temperatures below normal. However, temperatures did bounce around quite a bit as highs were in the 40s, 50s, 60s, 70s and 80s at various times during the month. Ultimately, the monthly average of 53.0 degrees made it the 2nd warmest April on record for Rochester. Precipitation for April was below normal with a bulk of the 1.62 inch total falling on just 3 days. The first rumbles of thunder for 2010 came on the 2nd.
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May rounded out the spring months with more mild conditions, finishing over 2 degrees above normal. The month did start out cool though with temperatures below normal 9 out of the first 14 days. Highs could not climb out of the 40s on 4 of those days. However, summer started to exert itself during the second half of the month as highs warmed into the 70s and 80s, reaching or exceeding 90 twice. The warmest temperature for 2010 occurred on the 24th with a 94 degree high. May also continued the trend of a dry spring as it came in 1 ½ inches below its monthly normal. Of what fell, 90% of it came in the first two weeks. After that, measurable rain occurred on only 2 days for a total just under ¼ of an inch.
The spring of 2010 was a dry but warm one. The total of 4.71 inches made it the 6th driest on record for Rochester. Meanwhile, the very mild temperatures led to an average of 50.2 degrees for the spring months, making it the 2nd warmest spring on record
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While the spring was dry, June would get the summer months off to a soggy start. Measurable rain fell on 20 of the 30 days, with 11 of those recording a quarter inch or more of accumulation while three days had over an inch. Typically June experiences 11 days with measurable rain. Rain was so prevalent during the month that the longest dry period was at month’s end with a rain free last 3 days. The monthly total of 7.79 inches made it the 7th wettest June on record. The ever present rain, and clouds that produce it, helped keep temperatures from warming much. The average temperature was still a degree above the monthly normal, but highs were in the 60s on 5 days and topped 80 degrees just 8 times.
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July would trend toward more normal precipitation with rain falling on just 8 days of the month. The normal is 11. However, the rain would come in chunks, with 6 of the days recording around ½ inch or greater. July stayed relatively warm with only one day of below normal temperatures. There was no significant warm periods though as high stayed mostly in the low 80s, cracking 90 only once (91 on the 14th).
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The summer would end on a warm note as the August average of 72.7 degrees was 5 above its normal, and also made it the 9th warmest August on record. While there were no 90 degree days, highs were in the mid to upper 80s almost 70% of the time and it did reach 89 four times. It was a relatively dry end to the summer with below normal precipitation for August. One day accounted for 50% of the month’s total, with 1.95 inches on 13th (a record for that day).
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Mother Nature would turn the faucet wide open for September as almost 10 inches (9.95”) of rain soaked Rochester. It was the 2nd wettest September on record and 7th wettest month overall. However, 80% of this total fell on just 3 days, with 4.34 inches of that coming on the 23rd. This was a record for that day and also the 7th wettest day on record for Rochester. While September was around the normal for temperature, it was an abrupt downward turn from the summery temperatures of late August. An 86 degree day on August 30th gave way to a cool 61 by September 3rd. Highs reached 80 or greater on three days, but failed to warm above 60 three times.
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Conditions could not have been better for enjoying the fall colors as the first 3 weeks of October were mild, dry, and quiet. High temperatures topped 80 degrees on the 8th through the 12th, with a 90 degree day on the 9th. This is the latest date on record for 90 degree warmth in Rochester. It was also very dry over this period, with only a trace of rain, and the winds were relatively light with ample sunshine. The opposite would be true for the last 9 days of the month thanks to a change in the mild and dry weather pattern. It would rain for 4 straight days, with the entire month’s total of 0.79 inches falling on the 23rd through 26th. Temperatures also returned to seasonable levels. However, more significantly was a storm system that roared across the region on the 26th and 27th. A low pressure system tracked out of the Southern Plains, strengthening as it moved across the Upper Mississippi River Valley. While showers and thunderstorms did accompany the storm, it was the winds and the strength of the low pressure that made this storm note worth. This 2-day wind storm brought gusts of 50 to 60 mph to much of the region, with a peak of 58 in Rochester. The pressure was so low in the storm that it set state records for lowest pressure in Minnesota and Wisconsin. Rochester also experienced its 3rd lowest barometric pressure at 972.9 millibars.
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November was the 9th consecutive month with above normal temperature. The warmest stretch was 4 days of mid to upper 60 degree highs on the 8th-12th. However, the latter half of the month brought 7 days where highs did not warm above freezing. While it was a wet month compared to its monthly normal, the bulk of November’s rain (75%) fell on only two days - the 12th and 13th. The first measurable snow of the winter season also came during this time, with 0.7 inches on the 12th. Unlike the lighter winds of October, November was the breeziest month in Rochester with most days averaging around 13 mph.
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Mother Nature would make up for the lack of snow in November, and then some, as several snow storms would impact Rochester. The 41.3 inch total would make it the snowiest December on record and the snowiest month all-time. The first storm would bring accumulating snows on the 3rd and 4th with 9 inches. Within a week, a more significant storm would drop over a foot of snow on the 10th and 11th (16.0 inches). The 15.0 inch total on the 4th made it the 3rd snowiest day on record for Rochester. Snow would keep coming, with 6.2 inches on the 15th and 16th, 6.1 on the 20th, and another 3.4 on Christmas Eve. A warm up toward the end of the month would eat into the 29 inch snow pack, cutting it almost in half. It was a cold end to 2010 as December averaged around 2.5 degrees below normal. Most of that cold came in the first half of the month.
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2010 will be remembered for its precipitation, both for its very wet and dry periods. While the 39.85 inches made it the 9th wettest year on the record, it did not start out that way. The first 5 months of 2010 were 4 inches below normal, with the first snowless March on record for Rochester. The rain came in June though, and copious amounts would continue to fall through September. The 26.44 inches was the 3rd wettest June through September stretch on record. After a brief break from the above normal precipitation in November and October, December brought record snow by the shovel full. Overshadowed by all the precipitation was that it was also a very mild year, with the 46.0 average making it the 9th warmest on record. Spring was especially warm (2nd all time).
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