Fall Foliage Map

When will fall arrive in your area? 

This interactive map will predict peak foliage times across the United States.

Fall will soon be arriving, and with it, one of nature’s most stunning shows: the annual changing of the leaves.  For those who want to see the season in all its glory, a new interactive map reveals just when the colours of leaves will peak in different regions of the US.  This year, the map shows that peak viewing times for most parts of the United States is between the 10th and 17th of October.

‘While scientifically the concept of leaves changing colors is fairly simple, the ability to accurately predict when they will peak is very difficult due to the number of factors.  ‘A few of the major factors impacting when the leaves will peak include temperature, sunlight, precipitation and soil moisture.’  The predictive map uses a complex algorithm that computes over 37,000 pieces of information in order to accurately forecast when fall peak will occur at the county-level.  It includes calculations on historical temperatures, historical rainfall, forecast weather patterns and historical leaf color changes.  ‘Once we have accumulated the data, there are manual changes we then make to the data set based on our knowledge of the topic,’ said Melton.

The transition to vibrant oranges, reds and magentas is down to a range of chemical compounds – including those that make carrots orange and tomatoes red.  Bournemouth-based teacher Andy Brunning who is the author of Compound Interest, explains that the compounds – chlorophyll, carotenoids, flavonoids – are present in leaves all year round, but become more noticeable at this time of year.  Chlorophyll is the chemical compound responsible for the green coloration of most leaves.  The chemical is held within chloroplasts in the cells of leaves and is an essential ingredient in photosynthesis, in which plants use energy from the sun to convert carbon dioxide and water into sugars.  Plants need warm temperatures and sunlight to produce chlorophyll so as fall begins and the nights draw in, chlorophyll production slows and the existing amounts of chemical compounds in the leaves decomposes.  As a result, other compounds present in the leaves are more noticeable, such as carotenoids and flavonoids, creating a change in color.


‘The Nationwide Predictive Foliage Map is unique – it is one of the only fall maps that offers county-level prediction for the entire continental United States,’ said Melton.  ‘Due to the drastic changes in temperature and moisture each year, the peak leaf season can occur at very different times each year.’  ‘The map will help fall fanatics everywhere better understand when the fall season will arrive.’

The peak for fall foliage in my home state of Maryland is the third week of October!

Click the following link to open the interactive mapping:

Fall Foliage Map