Months With Warmest & Coldest Reading Just A Few Days Apart

 

 

For the purposes of this analysis, I've gathered together months that had their coldest and warmest temperature one or two days apart.  On average, this has happened about once every two-and-a-half years.  The difference between the coldest and warmest reading has been, on average, 42 degrees (ranging between swings of 29 and 61 degrees).  

I've limited the months in this analysis to those with "solo" occurrences, i.e., months in which the hottest and coldest temperature occurred on just one date.  Through December 2025 there were 61 months that met this criterion.  The last time it happened was in September 2025, when the month's warmest reading   occurred on 9/6 (86°), and the coolest reading on 9/8 (56°).  Here are a few other observations: 

• By month, February has had the most instances (nine), while September had the fewest (two).  By season, winter has had 20 such months, summer had 15, spring had 14, and fall has had 10 months.

• Although the average time between occurrences has been 2-1/2 years, in 1961 it happened in consecutive months (May and June).  And there have been four instances in which this type of month was just a month apart from the other:  Oct./Dec. 1871; Dec. 1882/Feb. 1883; Aug./Oct. 1894; and July/Sept 2025.  (There have been no instances in which a month's temperature extremes occurred on the same day). 

• The longest hiatus, which started in December 2009 recently ended in June 2023.  This is in contrast to the 15-year period between 1887-1901 when there were 13 months which had their warmest and coldest readings 1-2 days apart.  (Including five consecutive years, 1891-1895.)

 

GREATEST SWINGS IN A MONTH'S WARMEST-COLDEST TEMPERATURE WHEN THEY OCCUR TWO DAYS APART

>  March 1987/ 61 degrees/ from 76° to 15°

>  March 1988/59 degrees/ from 17° to 76°

>  December 1871/ 57 degrees/ from -2° to 55°

>  February 1967/ 56 degrees/ from 4° to 60°

>  April 1880/ 54 degrees/ from 26° to 80° 

 

GREATEST SWINGS IN A MONTH'S WARMEST-COLDEST  TEMPERATURE WHEN THEY OCCUR ONE DAY APART

>  January 1934/ 52 degrees/ from 58˜ to 6°

>  January 1913/ 45 degrees/ from 18° to 63°

>  June 1961/43 degrees/ from 96° to 53°

>  February 1947/ 43 degrees/ from 50° to 7°

 

Finally, there have been nine months in which the temperature extremes occurred on the first and last day of the month, most recently in June 2009.