Portsmouth Rhode Island Weather Almanac
Thursday, December 17, 2020
Cloudy, Moderate Snow, Dense Fog, Windy and Continued Cold
Climate Normal Period Climate Record Period  
1981- 2010   1893 - 2020  
    December 17, 2020     Record Record
Observed Daily Data   Observed   2019   Normal   Depart   Highest Lowest
Maximum Temperature   33   35   41   -8   58   in 2015   18   in 1932  
Minimum Temperature   23   28   27   -4   44   in 1996   -1   in 1942  
Average Temperature   28   32   34   -6   50   in 1928   10   in 1919  
Precipitation   .68   .45   .14   +.54   3.13   in 1973            
One Hour   .00   .08           .95   in 2000            
Snow   6.1   0.3   0.3   +5.8   6.1   in 2020            
Snow Depth   1   0           12   in 1904            
HDD   37   33   30   +7   55   in 1919   15   in 1928  
CDD   0   0   0   +0   0   in   0   in    
Maximum Dew Point   32   34   34   -2   58   in 1973   2   in 1951  
Minimum Dew Point   19   19   18   +1   43   in 1996   -12   in 1979  
Average  Dew Point   26   27   26   +0   48   in 1996   -2   in 1951  
Maximum Humidity   98%   96%   85%   +13%   100%   in 2016   60%   in 2009  
Minimum Humidity   85%   60%   56%   +29%   94%   in 1996   24%   in 1979  
Average Humidity   92%   78%   71%   +21%   97%   in 1996   50%   in 1953  
Maximum Barometer   30.10   30.16   30.13   -00.03   30.68   in 1899   29.64   in 1976  
Minimum Barometer   29.74   29.59   29.77   -00.03   30.32   in 1949   28.93   in 1970  
Average Barometer   29.92   29.88   29.95   -00.03   30.42   in 1949   29.39   in 1973  
Average Wind   14.5   8.9   8.4   +6.1   19.7   in 2000   1.2   in 1962  
Direction   NNW   NNE   WNW       SSE         NNE        
High Wind Gust   42   26   26   +16   53   in 2000   10   in 1962  
Direction   NNW   NNW   WNW       WSW         NNW        
High Heat Index                                      
Wind Chill   9   21   17   -8             -9   in 1972  
Maximum Water Temp   46.8   41.5   45.6   +1.2   52.3   in 2011   41.3   in 2013  
Minimum Water Temp   44.1   39.4   43.1   +1.0   49.6   in 2015   38.4   in 2010  
Average Water Temp   45.5   40.5   44.4   +1.1   50.5   in 2011   40.2   in 2013  
Sunrise/ AM Twilight   7:06:41 AM   6:35:22 AM            
Sunset / PM Twilight   4:17:21 PM   4:48:40 PM            
Length Of Day   9:10:40                          
Special Conditions   Dense Fog, Haze                            
Comments      
    December 17, 2020     Record Record
Month-to-Date Summary   Observed   2019   Normal Depart Highest Lowest
 Avg Maximum Temperature   44.5   43.3   44.1   +0.5   54.6   in 2015   30.5   in 1904  
Avg Minimum Temperature   32.6   30.2   30.4   +2.2   42.0   in 2015   16.5   in 1989  
Average Temperature   38.8   37.1   37.2   +1.6   48.6   in 2015   24.8   in 1904  
Total Precipitation   4.23   5.27   2.49   +1.74   7.74   in 1936   .27   in 1998  
Total Snow   8.4   8.3   3.4   +5.0   20.6   in 1981   0.0   in 2015  
Total HDD   446   475   468   -22   683   in 1904   279   in 2015  
Total CDD   0   0   0   +0   0   in         in    
Avg Maximum Dew Point   38.2   38.4   36.0   +2.2   49.1   in 2015   18.4   in 1989  
Avg Minimum Dew Point   24.7   22.7   20.9   +3.8   37.6   in 2015   -0.8   in 1989  
Average  Dew Point   31.6   30.9   28.5   +3.2   43.5   in 2015   8.8   in 1989  
    December 17, 2020     Record Record
Year-to-Date Summary   Observed   2019   Normal Depart Highest Lowest
Total Precipitation   41.11   54.77   46.47   -5.36   63.81   in 1983   27.14   in 1965  
Total Snow (since Jul 1 20)   9.0   8.3   4.5   +4.5   21.1   in 1898   0.0   in 2015  
Total HDD (since Jul 1 20)   1239   1465   1500   -261   1995   in 1904   1074   in 2015  
Total CDD (since Jan 1)   871   731   563   +308   871   in 2020   290   in 1902  
                                   
Hour-by-Hour Weather For December 17, 2020  
Climate Weather for December 17  
Weather History For December 17  
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