Phenology

Observations by Gary Fewless for Green Bay WI (Lat.N 44.51° Long. W 88.02° ), except as noted. For flowers lacking conspicuous petals or sepals I define "anthesis" as release of pollen by mature anthers.

Sep 2010 Mouse-over the photo for the identity of the subject early Fall colors, UW-Green Bay Sep. 22, 2010

Date	Observation (Click on links for photos)
Sep 27	Green Bay reached a low temperature of 38 degrees this morning, our lowest temperature since May 8 (142 days). There were frost "watches" widely for northeastern Wisconsin this morning.
Sep 24	Heavy rains yesterday and last night and now strong winds WSW this morning in excess of 20 MPH (peak wind 47 MPH). Temperatures remained very warm over night, falling only to 69° F at 6:00 a.m. and then to 61° at 8 a.m. It fell to 59° by 9:00 a.m. Here's a graph of the unusual sequence of temperature for the day, beginning at midnight and ending at 4 pm..
Sep 23	Rain began last night and continues through the day. Green Bay's 2.52 inches was a record rainfall amount for this date. The previous record was 1.34 in 1970. One of the highest amounts I found was 4.12 inches at Wisconsin Rapids, also a record for the day. Flood advisories were issued widely in northeastern Wisconsin. Rain continues into the afternoon and more predicted for tonight. Here's a photo of local flooding along Baird Creek Road this morning. The movement of a new air mass brought rising temperatures through the evening, that peaked at 78° F between 9 and 10 p.m. Here is a photo of Salix discolor (pussy willow) in flower Sep 23, 2010. The normal flowering period is April.
Sep 22	The progression of leaf color is accelerating. Here is a photo of Fraxinus americana (white ash) and Parthenocissus vitacea (Virginia creeper) on the UW-Green Bay Campus. Here is a series of 3 photos showing color change for Rhus typhina (staghorn sumac) on the UW-Green Bay campus. The same species in a sheltered site at the edge of a woods just a short distance away is still fully green.
Sep 21	A very warm and humid day throughout northeastern Wisconsin with highs in the upper 70's.
Sep 19	The morning low temperature was 40° F in Green Bay, our lowest temperature since May 11.
Sep 15	The tall prairie grasses on UW-Green Bay's Cofrin Arboretum are at their peak, as here in Sorghastrum nutans (Indiangrass). Rhus typhina (staghorn sumac) is among the earliest to change leaf color in the Fall. this photo shows change over a 6 day period from 9/9 to 9/15.
Sep 12	The early stages of Fall leaf color have begun, but where the understory is moist, most ground layer plants are still green, as in this Adiantum pedatum (maidenhair fern) in Brown County.
Sep 6	Today I found a few flowering plants of Viola adunca (sand violet) in Marinette County. Normally this species flowers in May and early June, but it appears that on occasion a small number of plants can flower into August or even September.
Sep 5	The fruits of Ilex mucronatus (mountain holly) are now ripening, ForestCounty. More photos.
Sep 3	Trees in northeastern Wisconsin have been very robust this summer for the most part, perhaps due in part to the abundant rain. There was very little sign of the approaching autumn in local forests, except for diseased and otherwise stressed individuals or distressed branches of otherwise healthy plants. Here you can see the early signs of leaf change in our Rhus hirta (staghorn sumac) at UW-Green Bay. It is usually one of the first common species to change color each autumn.
Sep 1	Quercus rubra (red oak) acorns are maturing, Florence County, WI.