Precipitation Trends for the past 114 years

We hear all kinds off theories about global warming and precipitation with a majority of them predicting increasing drought. Here is what has been happening in New Hampshire.
The monthly plots from 1895 to 2009 are below along with their calculated intermediate term (33 year) and short term (11 year) moving average.

Here is what the last 114 years looks like.

New Hampshire Annual Precipitation 1895 to 2009

We don't see any drought here. The annual increase in the 11 year running average is 6.14 inches and the 33 year running average is 5.07 inches.

Now lets look at the months


The January plots from 1895 to 2009 show the actual with trend lines. The moving average line for the 33 years 11 years are both showing decreasing precipitation.

January Precipitation 1895 to 2009



The February plots are showing a slightly decreasing trend for both the 11 and 33 year moving average.

February Precipitation 1895 to 2009



The March plots are showing a leveling out since the 1960's for the 11 year moving average and a slight decrease for the 33 year moving average.

March Precipitation 1895 to 2009



The April  plots are showing a steady 33 moving average since about 1930.

April Precipitation 1895 to 2009



The May plots are showing a very slight increase in the 33 year moving average since about 1930.

May Precipitation 1895 to 2009



The June trend is currently showing an increase for both the 11 and 33 year moving average since around 1995.

June Precipitation 1895 to 2009



The July trend is currently showing an increase for both the 11 and 33 year moving average since around 1980.

July Precipitation 1895 to 2009



The August plots were falling until the 1950's and have been increasing since then.

Aug Precipitation 1895 to 2009



The September plots show a declining trend.

September Precipitation 1895 to 2009



The October plots show a steady increase for the full data period.

October Precipitation 1895 to 2009



The November plots show a slight declining trend since about 1970..

November Precipitation 1895 to 2009



And finally the December plots appear to have a some long term cyclical characteristics.

December Precipitation 1895 to 2009



Summary of the annual average temperature trend by month for the past 100 years for both 11 and 33 year running averages.

Monthly Changes in Precipition 100 Year Short Term

Monthly Change in Precipition 100 Year Long Term






Contact Us