Last Five Years in NH Were Wettest on Record, New UNH Research Shows
By Lori Wright, Media Relations
January 27, 2010
If you feel New Hampshire has been more soggy in the past few years, you’re not imaging it. New research from UNH shows that the last five years have been some of the wettest in more than 100 years.
According to Mary Stampone, assistant professor of geography and the New Hampshire State Climatologist, the years from 2005 to 2009 have broken records for monthly, seasonal, and annual precipitation totals. Specifically, the years 2008, 2005, and 2006 are the top three wettest since 1885 when the state began keeping records.
Stampone presented her research on long-term New Hampshire precipitation patterns recently at the American Meteorological Society's 90th Annual Meeting.
“Above average precipitation along with recent extreme precipitation have many new Hampshire residents concerned about a wetter and more hazardous future for the state. However, extreme as these events may seem, statistical analysis of total annual precipitation recorded at six New Hampshire weather stations from 1895 to the present indicates similar wet periods are present and are typically followed by extended periods of drier conditions,” Stampone said.
The following are the wettest and driest years for New Hampshire’s six weather stations:
- Berlin: wettest, 1954; driest, 1948.
- Concord: wettest, 2008; driest, 1965.
- Durham: wettest, 2008; driest, 1941.
- Hanover: wettest, 1983; driest, 1963.
- Keene: wettest, 2005; driest, 1964.
- Nashua: wettest, 2008; driest, 1941.
Stampone also found that the period after 1931 has generally been wetter. From 2004 to the present has been wetter than 1895 to 2003, and includes three of the wettest years
for stations within climate zone 2.
Stampone said it’s difficult to know now whether or not the last five years indicate a new precipitation pattern or if it indicates a shift back to the type of cyclical pattern of multi-year wet periods followed by extended dry ones.
Prior to 1970, the state experienced a cyclical pattern of three to five wet years followed by a five to seven year dry period. After 1970 the pattern switched to a period of high interannual variability where every year was very different from the previous one. Since 2004, New Hampshire has been in an extended wet period that is similar to the wet periods recorded prior to 1970, but the current period is wetter for southern parts of the state (climate zone 2). It is worth noting that this pattern is not seen in the Berlin record, indicating that the factors influencing precipitation in northern (climate zone 1) and southern areas are different.
“This year will be a good indication as to whether or not we will stay wet or move into a drier period like we used to prior to 1970. We'll have to keep our eyes on the skies,” she said.