Lake Michigan coastal dunes experience warm summers and cold winters,
as seen on the graph of mean monthly temperatures recorded at Muskegon,
Temperature has little
direct effect* on sand movement by wind, but indirectly it has great
influence on dune processes. Temperature is part of local climate
controls on the types of vegetation present and the length of the
growing season. Below-freezing temperatures in the winter cause
water to freeze in the ground (ground-freezing), at the surface
(ice), on the lake (coastal ice), and in the atmosphere (snow).
Rising temperatures in the spring produce melting and thawing with
noticeable effects on the coastal dunes.
1971-2000 monthly normals as published in the
Climatography of the United States No. 20 available from
the National Climatic Data Center at www.ncdc.noaa.gov.