U.S. Department of the Interior 

U.S. Geological Survey

Fact Sheet FS 2005-3002

January 2005

Historical Changes in Lake Ice-Out Dates as Indicators of Climate Change 

in New England, 1850-2000

Introduction 

 Lake ice-out dates, or the dates of 

ice break-up, are the annual dates in 

spring when winter ice cover leaves a 

lake. Several studies in the last 15 years 

have used lake ice-out dates in the 

Northern Hemisphere as measures of climatic variability and change. Very few 

lakes in New England have been analyzed, even though a remarkable amount 

of lake ice-out data have been recorded 

and saved in New England during the 

past two centuries. For some lakes in 

New England, such as Moosehead Lake 

in Maine, ice-out dates were important 

for local steamship transportation. Data 

from other lakes, such as Richardson 

Lake, Maine, were important for annual 

log drives. Individuals have collected 

and saved extensive data because of general curiosity and community interest. 

For Damariscotta and West Grand Lakes 

in Maine, the same family has been collecting ice-out data for three generations. 

The purpose of this study was to document and analyze the historical lake iceout dates in New England.

Key Findings

 Ice-out dates from 29 lakes in New 

England with 64 to 163 years of record 

were assembled and analyzed for this 

study (Hodgkins and James, 2002; 

Hodgkins and others, 2002). Twenty-two 

of these lakes are in Maine, four are in 

New Hampshire, and three are in Massachusetts. 

 Ice-out dates have become significantly earlier in New England since the 

1800’s. Ice-out dates changed between 

1850 and 2000 by 9 days in northern and 

mountainous areas of New England (primarily northern and western Maine) and 

by 16 days in more southerly locations 

(figs. 1 and 2). Changes in the ice-out 

dates over time were very consistent 

between lakes within each of these two 

areas of New England. 

 About half of the year-to-year variability in the lake ice-out dates is 

explained by historical March-April air 

temperatures. The ice-out dates of the 

two areas have a different response to 

changes in air temperature though. The 

ice-out dates in the northern/mountainous areas are less sensitive to changes in 

air temperatures than the ice-out dates in 

the more southerly areas. This may be 

due to the typically higher amounts of 

snow on the lake ice in the northern/

mountainous areas in late winter/early 

spring. The estimated late winter/early 

spring air-temperature warming in both 

areas of New England since 1850, based 

on the relation between lake ice-out 

dates and air temperatures, is about 

2.6oF. Changes in lake ice-out dates over 

time can affect important characteristics 

of lakes, such as the rate of change of 

summer oxygen levels (Stewart, 1976), 

and the health of important parts of the 

food chain (Maeda and Ichimura, 1973; 

Porter and others, 1996).

Ice-out on Sebago Lake, Maine, spring 1985

Changes in water resources over time may affect public and private water 

supplies and the health of aquatic ecosystems. The U.S. Geological Survey 

is studying the relation between climate and water-resource variables in 

Maine and New England to provide resource managers, the scientific community, and the public with better information about the sensitivity of water 

resources to climate change and variability. The long-term collection and 

availability of high-quality water-resources data are crucial to these efforts.
U.S. Department of the Interior 

U.S. Geological Survey

Fact Sheet FS 2005-3002

January 2005

References

Hodgkins, G.A., and James, I.C. II, 2002, 

Historical ice-out dates for 29 lakes in 

New England: U.S. Geological Survey Open-File Report 02-34, 32 p.

Hodgkins, G.A., James, I.C., and Huntington, T.G., 2002, Historical changes in 

lake ice-out dates as indicators of climate change in New England, 1850-

2000: International Journal of Climatology, v. 22, p. 1819-1827.

Maeda, O., and Ichimura, S.E., 1973, On 

the high density of a phytoplankton 

population found in a lake under ice: 

Internationale Revue der Gesamten 

Hydrobiologie, v. 58, p. 673-685. 

Porter K.G., Saunders, P.A., Haberyan, 

K.A., Macubbin, A.E., Jacobsen, T.R., 

and Hodson, R.E., 1996, Annual cycle 

of autotrophic and heterotrophic production in a small, monomictic Piedmont Lake (Lake Oglethorpe)—

Analog for the effects of climatic 

warming on dimictic lakes: Limnology and Oceanography, v. 41, p. 1041-

1051.

Stewart, K.M., 1976, Oxygen deficits, clarity and eutrophication in some Madison Lakes: Internationale Revue der 

Gesamten Hydrobiologie, v. 61, p. 

563-579.

—By Glenn A. Hodgkins, Ivan C. James II, 

and Thomas G. Huntington

For more information please contact:

District Chief

U.S. Geological Survey

196 Whitten Road

Augusta, Maine 04330

Telephone: (207) 622-8201

Email: dc_me@usgs.gov

Website: http://me.water.usgs.gov

Figure 1. Ice-out dates over time for Damariscotta Lake, Maine, and a smoothed line 

through the dates.

Figure 2. Smoothed lines of ice-out dates over time for the eight lakes in New England 

with the longest periods of record. The top four lines represent lakes in northern and 

western Maine and the bottom four lines represent lakes in southern Maine.

Apr

30

Apr

20

Apr

10

Mar

31

Mar

21

Mar

11

Date of ice-out

1850 1900 1950 2000

Year

May

10

May

20

May

10

Apr

30

Apr

20

Apr

10

Mar

31

Mar

21

Date of ice-out

1800 1850 1900 1950 2000

Year