‘When did Swallows First Arrive to Kinderhook, NY in 1835?’: Why You Might Care & Why You Can Now Know.


from The New England Farmer by Samuel Deane, 1822.

Weather forecasting and climate study have changed not only how we plan our days but also, I think, how we envision our lives. Most of us regularly consult the weather forecast as we decide what we will do or wear during the next day or even week. Imagine, for a moment, what it would mean to your logistics and psyche if you were informed that it was going to rain more or less solidly for the next five days.

fuertes barn swallow
For a Then & Now exploration of Barn Swallow arrival dates, CLICK ON THE ABOVE IMAGE.

That thought experiment might help illustrate one of the primary initial motivations behind the development of the science of meteorology in North America: agronomy. Given our current dry spell, if you’re a farmer, the thought of a good soaking rain might be a relief, and might inform whether or not you decide to plant now or wait until next week. Our modern ability to make those predictions is clearly of use to gardeners of all ilks.

However, despite the advances we have made in short-term weather forecasting, our abilities to predict weather at the larger scale remains sketchy. The National Weather Service dares to make predictions nearly a week in advance, but, in my experience, that seems to be pushing the envelope, and two or three days out seems to be the usual limit of reliability. Despite centuries of efforts, the Farmers’ Almanac year-long forecast may pique one’s curiosity but rarely alters one’s plans.

Two hundred years ago, when access to food grown elsewhere was more limited, knowledge of what the growing season would bring, even a couple of weeks ahead of time, was even more crucial. This was especially true in Spring, when an earlier planting might mean quicker crops but a greater risk of frost.

In a similar vein, while local experience can give us important insight into when to plant familiar crops, what happens when you need to know when, or even if, to plant a novel crop? Plant hardiness maps and growing-degree-day models give the modern planter some hints, but what was a St. Lawrence County farmer of 1830 to do if a cousin on Long Island sent along some new but highly recommended seeds? If that cousin were to say ‘plant these around the 25th of April’, that advice might, given the wide difference between these two NY climates, be worse than useless. If, on the other hand, the cousin were to say something like, plant these ‘when you plant your corn’, or ‘a week after your cherries bloom’, or even, ‘round about when your Martins arrive’, then the advice would be more usable.

For ‘state of the Spring’ exploration of the historical data, CLICK ON THE ABOVE IMAGE.

It was apparently this desire to facilitate the sharing of agronomic advice that prompted the New York State Regents to begin their three-decade long exploration of the State’s climates and seasons. As Simeon De Witt, the man who some 30 or more years later was to initiate the Regents’ work, put it in 1792,

as the state of vegetation is very different in different climates at the same time, without knowing what allowances are to be made on this account, the farmer, in one climate, will not be able to apply in his practice the experiments on husbandry made in another.

He continued that such work will necessitate,

besides common observations on the weather, observations on the annual commencement, progress and maturity and decay of vegetation, made in various parts, for a number of years; the averages whereof may be taken for standards by which to exhibit a comparison of climates… The remarks on the vegetation should commence with the first appearance of it in the Spring, and be made on grass [a more encompassing term historically] in general, the budding of trees, the flowering of plants, the maturity of the several kinds of winter grain and fruit, and the falling of leaves, and other symptoms of decay in the fall.


In the early 1800s, the New York States Regents supervised, amongst other educational institutions, some fifty or so ‘academies’. Academies were apparently public/private hybrids that were the combined high schools and prep schools of their era. They offered additional instruction beyond the traditional “3 R’s” of the basic public schools. Aside from advanced courses in reading, ‘riting, and ‘rithmitic, students were taught topics such as classical languages, rhetoric, surveying, philosophy, botany and astronomy. Graduates of academies might hope to continue to college or to enter business, the clergy or education. As market forces probably dictated, academies were scattered across the State. What better network of facilities and able minds for beginning to unravel the mystery of the State’s climatic topography?

Like yellow? For an exploration of why the yellow of Forsythia (left) was missing in our historical data and of the flowering and leafing out patterns of Maple’s (right), CLICK ON THE ABOVE IMAGE.


Thus on 1 March 1825, the Regents approved De Witt’s proposed meteorological project. Participating academies received a New Lebanon-made Kendall thermometer and rain gauge; however, it was a BYOWV (Bring Your Own Wind Vain) affair. They also received instructions not only on how to collect and report their measurements but also on how to make a variety of additional observations, from notes on the ‘progress of the seasons’ to descriptions of celestial events such as Aurora and distinctive clouds or solar phenomena.

The effort was maintained until the Civil War, bolstered after 1850, by a nationwide project undertaken by the Smithsonian Institute and modeled substantially on the NY enterprise. There are a wealth of data. By the time we have finished entering the phenological (i.e., the seasonal events) information, we expect to have over 12,000 individual records of when certain plants flowered, when frogs called, when birds arrived, and when farmers planted or harvested.

These data are a trip back in time, a geographically-specific glimpse of human and natural history that starts almost 190 years ago. One can find arrival times for Passenger Pigeons, flowering times for bygone hedge plants, and a diary of farm activities. However, this collection is not meant just as a portrait of the past, but also as a perspective on the present.

currants plate
We used the ‘Progress of the Seasons’ data to explore patterns mid-19th century fruit growing in NYS. If you’re curious, CLICK ON THE ABOVE IMAGE.

In these days of changing climate, the records can give us a valuable historical baseline for charting change, in much the same way as work with Thoreau’s journals has helped spur climate change understanding in Massachusetts (see link below). Furthermore, what a story and suite of activities to motivate the creation of a school-based phenology network! The fact is that finding equivalent modern information for comparison with these historical records is not so easy (although links below will lead you to some valuable modern initiatives). A multi-school program could thus not only provide useful data, but also involve students in a diverse combination of historical, biological and analytical activities.

The search for immediate weather and climate understanding has largely become the realm of complex models and highly developed measurement technologies such as weather satellites. Perhaps this has long since antiquated the application of the Regents records to the questions for which they were originally intended. And yet, in ways probably not dreamt of by those who gathered the information, these data have become even more pertinent to our understanding of climate and change, not at the scale of days, weeks or years but at the scale of decades and centuries.

Our goal with the first phase of the Progress of the Seasons Project is to try to highlight this relevance by digitizing the data and sharing it in easily accessible and stimulating forms. If this sparks interest, then we can think of developing ways of bringing the Project into classrooms in future years.


We looked at Frog calling date as a way of predicting Apple and Cherry bloom; and also at how Frog calling and Apple flowering dates varied between two sites. To explore our conclusions, CLICK ON THE ABOVE IMAGE.


The work is on-going. We have been presenting weekday summaries in the form of “this date in phenological history” postings to our Progress of the Seasons blog (which has provided some of the examples included above) and have created a New York State Phenological History Browser. Want to know when those Swallows arrived in Kinderhook in 1835? Just use our browser to look it up! (And thank some forward-thinking 19th century scientists for your ability to do so.)


More Useful Links

Our Background Page – More information on the Regents’ project, including a map and list of participating sites

Field Guide to the Seasons – Local author Janice Goldfrank’s nifty ibook guiding you through 19 seasons in the year, from Icicle Season through Blueberry Season and on into Oak Season.

The National Phenology Network – engrossing displays and reports on data nationwide; we may submit any regional records we gather to them for inclusion in the larger data set.

The New York Phenology Project – a New York State affiliate of the national network; has some dandy resources for following the phenology of particular species.

Journey North – a live tracking of bird and butterfly migrations and various other seasonal events, great maps.

Project BudBurst – A plant phenology project with lots of materials for teachers.

The Phenology of Walden Pond – Richard Primack’s Boston University web page and blog; Dr. Primack has been comparing  Thoreau’s phenology data with those of the modern day. A great side-by-side comparison for New York.