Beta testing for the new Nature's Notebook app is officially underway! This is a period where a small group of observers are testing the new app. We have already heard valuable feedback and caught some important bugs. We have open beta testing opportunities for backyard observers, Program members, and Program administrators. We so appreciate your help!

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Earlier this year, the Nature's Notebook Community Forum went live. The forum provides a space to share resources, ask questions, and make connections with fellow observers. Make sure you're logged in with your Nature's Notebook account to access content and post.



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We are once again offering the Local Phenology Leader Certification Course this fall from September 14 - November 20. The course is designed to help you plan and implement a long-term Nature's Notebook Local Phenology Program and is a great resource for educators or researchers looking for help getting phenology monitoring set up. The course is online and interactive; participants work with peers across the country and with USA-NPN staff to gain skills in program planning, volunteer recruitment, phenology monitoring, data visualization, and collaboration.



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The Thermal Calendars tool indicates when thresholds of accumulated warmth are met each year in the northeastern U.S. Local management efforts can benefit from understanding when problematic insect pests are expected to reach life stages and use the Thermal Calendars to determine when they may cause the most damage or are most readily controlled. 



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Thermal Calendars info sheet »

Following a lapse in availability, the seasonal climate measures (average temperature, total precipitation, accumulated growing degree days) available for download with USA-NPN observational data have been updated through 2024 and 2025. You can request these additional variables when you query data through the Phenology Observation Portal and using the R package, rnpn.

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This spring, we added the Late Bloom Index to our suite of Spring Indices. The Late Bloom Index indicates when plants that bloom at the tail end of the season are flowering, effectively representing the end of the spring season. In conjunction with the Spring Leaf and Bloom Indices, the Late Bloom Index enables us to tell a more complete story about how spring unfolded. This year, all three indices were reached earlier than normal (1991-2020 average), and early fulfilment of the Late Bloom Index was especially widespread.



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The timing of phenological events in autumn like leaf color and leaf fall have important consequences for nutrient cycling, species interactions, and even tourism. However, there has been less research on autumn phenology than spring phenology and the effects of temperature, precipitation, and day length are not well understood.

To fill this gap, researchers used Nature’s Notebook observations of autumn phenology from woody plant species across the U.S. They found strong regional differences. Leaf color in the eastern U.S. was driven primary by summer temperatures, whereas in the western U.S., leaf color change was influenced more strongly by precipitation that occurred more than six months prior. Given these differences, the effects of climate change are likely to be complex. Increased temperatures may extend the growing season for some plants and increased drought may shorten the growing season for others.  

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Next month, the Botany 2026 meeting will take place in Tucson, Arizona -- the hometown of USA-NPN HQ! We'll have a strong presence at the meeting and look forward to connecting with you. Please stop by our booth in the meeting expo, attend one of our team members' presentations, and join us for a lunchtime phenology meet-up on Tuesday at noon!

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Barbara Templ, Emma Izquierdo-Verdiguier, and Koen Hufkens are inviting contributions to a special topic in the journal Frontiers in Plant Science. This Research Topic seeks to advance phenology research by exploring a diverse range of contributions. It aims to address underrepresented taxa and ecosystems, less studied phenophases and seasons, and the integration of multi-source data. To gather further insights into the ecological and societal consequences of phenological shifts, we welcome articles addressing, but not limited to, the following themes:

• Studies of underrepresented taxa (herbaceous plants, crops, grasses) and ecosystems (tropical, arid, urban, agricultural)
• Research on less studied phenophases and seasons, particularly autumn and reproductive stages
• Integration of multi-source data (field, remote sensing, phenocams, citizen science, experimental)
• Advances in modeling, scaling, and representing interacting environmental drivers
• Ecological and societal implications of phenological change, including mismatches and ecosystem feedback
• Innovations in data standards, infrastructures, and open science practices for phenology

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The 24th International Congress of Biometeorology will be held at the University of Novi Sad, Faculty of Sciences in Serbia in the summer of 2026. The Congress will be held from July 13th to 16th in 2026 using a hybrid format, which includes both onsite presentations/posters and online presentations.

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