In 2025, 3,545 observers like you contributed a total of 3.8 million phenology records! Read the 2025 Annual Report for more highlights of phenology accomplishments made possible by our partners and observers, and a letter from USA-NPN Director, Theresa Crimmins.

Read the full 2025 Annual Report »

March 16-20 is Phenology Week – a virtual celebration of the seasonal cycles of plants and animals. The purpose of Phenology Week is to celebrate you, our Nature's Notebook observers, Local Phenology Programs, and partners! We have a great week planned with virtual events each day and would love to see you there.

See what's on the schedule »

Sign up for Phenology Week emails »

We're excited to launch our new Nature's Notebook Community Forum, which provides a platform to share resources, ask questions, and make connections with fellow observers. Make sure you're logged in with your Nature's Notebook account!

Visit the Forum »

Many forests in North America are threatened by insect pests. In the northeastern U.S. and eastern Canada, outbreaks of spruce budworm occur rarely, but can last 4-6 years and devastate conifer forests. Budworms feed on new foliage of fir and spruce trees, limiting growth and even killing some individuals.

Recently, researchers confirmed that spruce budworms can also negatively impact eastern hemlock, an evergreen tree in the pine family that plays an important role in Maine forests and are also harvested commercially. This information is especially important now, with a current budworm outbreak in eastern Canada that is expanding into Maine. 

Hear from lead author, Rachel Poppe, at our Phenology Week Researcher Q&A session on Friday, March 20th at 12pm ET!

Read the Publication Summary »

Register for the Researcher Q&A »

According to Punxsutawney Phil, more winter weather is on the way! But what does the science say?

Our maps of heat accumulation provide a more informed look at how much heat has accumulated in different parts of the country so far this year. Our maps show that heat accumulation is ahead of schedule in much of the West, on time in the Midwest and upper Northeast, and behind schedule in the East. According to predictions from NOAA's Climate Prediction Center, Phil may be right for parts of the Northern Great Plains – more cool temperatures are on the way! Much of the Southwest and Southeast should see above average temperatures in the coming weeks. The Northwest, Midwest, and Northeast should see average temperatures.

To watch the progression of spring across the country, check out our spring forecast maps – updated daily!

Spring forecast maps »

Join the Nature's Notebook Nest - bring your questions and observations and chat with USA-NPN staff, fellow observers, and Local Phenology Leaders! These are standing monthly meetings on the first Monday of the month at 12pm PT / 3pm ET. Mark your calendars, next Nest is March 2nd!

Sign up for reminders about the Nest »