Mild December helped make 2023 warmest year on record in Berks
Jan. 8—At first glance, the only thing that seemed remarkable about the weather in 2023 for Berks County was the dearth of snow.
The summer months were unremarkable, with 20 90-degree days, just a tick above normal, and none of the hot weather months even made it into their respective warmest top 10s.
But the pervasiveness of warmth for the rest of the year was what was remarkable.
The 56.5-degree average for the year nosed out the 56.4 from 1998 for the warmest year in the 125-year Berks temperature database.
"All of the cooler months of 2023 have been warmer or much warmer than normal, while the intervening warmer months have been close to normal," said Berks weather historian Jeffrey R. Stoudt.
Stoudt calculated the 56.5. The National Weather Service office in Mount Holly, N.J., computed it to 56.4. The difference is in how the average is calculated: weighted versus nonweighted, averaging the days versus averaging the months.
The more precise calculation — Stoudt's — accounts for the highs and lows of the days individually. The less precise calculation gives mainly February too much weight, and since it's a cold-weather month, it can influence the final average.
Official measurements are taken on the automated equipment at Reading Regional Airport, but that's only been since early 1998. Previous to that locations were at Met-Ed and UGI Utilities Inc. periods from 1970 into 1998. Then there were the U.S. Weather Bureau locations in Reading from 1912 through the 1960s. Before that, measurements were taken in City Park by the city.
About 32 degrees
The other notable record was that there was only one "ice day" — the temperature didn't rise past the freezing mark — in 2023, and that was Feb. 4 when the low and high were 12 and 28 degrees, respectively.
"The year total undercuts the longstanding record lowest of three during 1949," Stoudt said. "That 4th of February would be the only day of the year that would be considered harshly cold."
The full-record-period average is 23. Eight years this century have exceeded that average, the most recent 2015. 1998 is tied with 1952 with only four ice days. 1977 and 1976 in heart of the deepest cold period in the records are on top with 45 and 41, respectively.
Also, there are the numbers of days the low temperature was 32 or lower. There were 80 of those in 2023, but it's not a record. The record is 67 from 1953, again in the midcentury.
2020 was a very warm year as well, but it, too, had 80. There are a few other years from the midcentury and 1998 with the count between 67 and 80.
An annual warm record still held by the mild midcentury years, however, is least-cold temperature during a year. That is 17 degrees during 1937 and 1956.
Another is the warmest 12-month period, which is 56.6 degrees from March 1931 through February 1932.
Precipitation
Turning to precipitation in 2023, there was the 3.9-inch all-time low snow total.
The annual precipitation total — rain and melted frozen precipitation — was 46.52 inches, 1.31 above the normal of 45.21. That 45.21 is the highest normal of the entire record period, which dates to 1869.
The weather service considers normal the average of the most recently completed three full decades, in this case 1991 through 2020. The deluges that ended last decade helped make that normal that high.
The wettest 12-month period on record is 75.80 inches from August 2018 through July 2019.
Other 2023 highlights
Stoudt's top weather events of last year included:
Torrential thunderstorm downpours and severe flooding of July 9 totaled 5.35 inches, a record for any date in July.
The EF1 tornado in the vicinity of Womelsdorf April 22, with light to moderate damage.
The extremely dry May, officially driest May on record and second driest on record of any month.
Heavy smoke from distant wildfires in June.
The soggy July at 10.07 inches fueled by the 9th. It was the fifth wettest July on record.
The third-warmest January on record with an average temperature of 40.7 degrees.
The early September heat wave of six days with 98 degrees on the 7th for year's hottest reading, then heavy thunderstorms, some locally severe contributed to a wet September.
December contributions
Last month turned in a fourth-warmest showing by average temperature among Decembers at 41.5 degrees. Since 1998, seven Decembers have taken spots among the 10 warmest, kicking many from the mild midcentury years off the list.
The warmest remains December 2015, which beat the previous warmest by more than 4 degrees, the equivalent of taking the checkered flag while the rest of the field is just rounding the fourth turn.
The only temperature date record last month was a 49-degree low on the 28th, which topped the previous mildest low for the date of 45 from 1940.
"December's mildness came courtesy of the daily low temperatures," Stoudt said. "It was the lack of harshly cold temperatures that did the trick. Only 15 of the 31 (lows) were freezing and none colder than 24 (degrees). December 1918 also had 24 as lowest. December 2015 had a lowest of 23. ... Four Decembers had less than 15 (lows freezing or lower), least nine in 2015."
There were two precipitation date records: the 18th and 27th.
"December precipitation was high to very high countywide, though with somewhat greater amounts toward Route 100," Stoudt said. "Yearly amounts slipped into substantial deficiencies first half of year. Then (a) few wet months, mainly July, September and December, whittled then ultimately rallied toward or slightly past yearly averages by New Year's Eve. Overall, eastern Berks ended slightly wetter than western Berks."
The standings
National Weather Service and U.S. Weather Bureau records for Berks County date from 1869 for precipitation and 1898 for temperature, and here's the tale of the year and its 12th month:
10 warmest years
—56.5: 2023
—56.4: 1998
—56.3: 1949
—56.3: 2012
—56.2: 1953
—56: 2020
—55.9: 2021
—55.7: 1931
—55.5: 1959
—55.3: 1921
—55.2: 1900
10 warmest Decembers (by average temperature)
—46.5: 2015
—42: 1923
—41.6: 2021
—41.5: 2023
—40.9: 1956
—40.8: 1998
—40.2: 2006
—40.1: 1931
—39.9: 2001
—39.7: 2011
10 wettest Decembers (precipitation in inches)
—9.89: 1983
—7.70: 2023
—7.41: 1996
—7.10: 1902
—7.05: 1973
—6.63: 1972
—6.22: 1884
—6.22: 2008
—6.17: 1977
—5.97: 1901
December specifics
—41.5: Temperature
—35.7: Normal
—7.70: Rainfall
—3.51: Normal
Records:
—49 degrees on the 28th: (mildest low; 45, 1940)
—1.88 inches on the 18th (precipitation; 1.30, 1869)
—1.53 inches on the 27th (precipitation; 1.40, 1930)
Berks Area Rainfall Networks precipitation totals (December, annual, in inches):
—Boyertown, 10.17, 47.89
—Henningsville, 9.74, 51.09
—Topton, 9.45, 54.69
—Elverson NE, 9.33, 46.87
—Shillington, 9.10, 54.28
—Morgantown, 8.93. 45.60
—Dryville, 8.84, 49.86
—Mohnton, 8.82, 50.38
—Wernersville, 8.77, 55.79
—Lincoln Park, 8.75, 54.06
—New Morgan, 8.69, 46.29
—Oley Furnace, 8.68, 48.86
—Cornwall Terrace, 8.65, 56.19
—Boyers Junction, 8.52, 53.32
—Reading E, 8.51, 50.38
—West Reading, 8.50, 51.55
—Knauers, 8.48, 45.06
—Lobachsville, 8.46, 45.22
—Fritz Island, 8.46, 48.33
—Wyomissing Highlands, 8.45, 49.97
—Cumru Township building, 8.39, 45.37
—Vinemont, 8.27, 46.80
—Womrlsdorf, 7.82, 48.13
—Shartlesville, 7.81, 50.71
—Auburn, 7.76, 52.03
—Greenfields, 7.73, NA
—Reiffton, 7.67, 47.26
—Bernville, 7.42, 49.14
—Mohrsville SW, 7.33, 48.33
—Mohrsville, 7.19, 49.17
—Hamburg, 7.13, 49.78
—Pine Grove, 6.23, 46.33
—Frystown, 5.04, 43.45
