Latest Score:


in 2019

score trend is flat over time
Weight: 10%

As our climate changes, it is predicted that there will be greater variability in annual temperatures, as well as warmer minimum temperatures in the winter. Failure to reach typical low winter temperatures can allow for non-native pests, pathogens, and plants to be better able to survive; further, our native trees may decline in health due to the rapidly changing climate1. More frequent free-thaw cycles can damage tree roots and can mobilize nutrients away from forests where they are needed. Here, we assess the change in annual minimum temperature in Vermont. As trees are adapted to the conditions they have experienced, deviations in minimum temperature from the long-term mean (both above and below) could be problematic to forests. Therefore, annual scores are computed as the change from the long-term mean.

1Rustad, L., Campbell, J., Dukes, J.S., Huntington, T., Lambert, K.F., Mohan, J. and Rodenhouse, N., 2012. Changing climate, changing forests: The impacts of climate change on forests of the northeastern United States and eastern Canada.

Minimum temperatures, which generally occur overnight into early morning, are increasing more than maximum temperatures. This trend is consistent with the Northeast region and is expected to continue. Rising temperatures can alter migration of some tree species.

Additional Resources

National Climate Assessment 2014

National Climate Assessment 2018

NCEI State Summary for VT

Interpretation provided by:

NOAA, Northeast Regional Climate Center at Cornell University (2020)


The score is calculated using a target value and the historical range of the the entire long-term dataset. The higher the score, the closer this year's value is to the target.

Once the score is computed for each year, the trend in scores over time is calculated. If the trend is significantly positive or negative, the long-term trend is marked as increasing or decreasing respectively.

Component Description
Scored as

Distance away from long-term mean (scaled 1-5)

Target value

Long-term mean

Directionality of scores

No change from the long-term mean is better.

Minimum value used in scoring

Data minimum - 10% of range

Maximum value used in scoring

Data maximum + 10% of range

Data of mean minimum annual temperature for Vermont were gathered from NOAA National Centers for Environmental Information1. We set the target for the dataset as the mean minimum temperature from 1961-1990 which is used as the baseline normal for climate comparisons by the Intergovernmental Panel on Climate Change (IPCC). The current year is scored for where it falls between the target and the upper scoring bounds (maximum value in the dataset) or the lower scoring bounds (minimum value in the dataset), scaled to be between 1 and 5.

1 NOAA National Centers for Environmental Information. 2018.