biodiversity homepage      

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.

October 2006

Oct 31 Today is midway between the autumnal equinox and the winter solstice (this date is sometimes referred to as a "cross-quarter" day).
Oct 26 The most common tree species in the Green Bay area have mostly lost their leaves : Fraxinus pennsylvanica (green ash), Acer negundo (Box elder), all the Populus species (cottonwoods, aspen), Salix (willows). The leaves of the white oak group (white and bur oaks) have mostly turned brown (remaining on the branches however), but Quercus rubra (red oak) still maintains some green leaves and some in the process of turning yellow or red. Acer saccharinum (silver maple) and Acer platanoides (Norway maple) are still mostly green in many locations. Also the alien, invasive buckthorn species Rhamnus frangula (glossy buckthorn) and Rhamnus cathartica (European buckthorn) are still fully green. You can find more information on the buckthorn species on the invasive plants web page.
Oct 25 Green Bay's low temperature of 22 °F is the coldest of the season to date (our lowest temperature since March 18).
Oct 24

There are still some leaves and a little good fall color left in the Green Bay area -- most notably in the oaks.

Here is the sequence of development for Rhus hirta (staghorn sumac) from May 3 to Oct 18, in the form of a movie/quick slide show. The photos were taken at about one week intervals, with one photo missed at the end of May and another in Mid August. The sequence runs from bare branches through leaf-out, to fall colors and back to bare branches.

Oct 18

Here's the last increment in the sequence of leaf color for Rhus hirta (staghorn sumac).

Oct 17 The water level in Green Bay has been conspicuously low lately. The September monthly average level for Green Bay was about 11 inches (.92 ft) above the record low level for the month (set in 1964).
Oct 15 Green Bay reached a low temperature of 24° F this morning.
Oct 14 WI DNR is reporting that lakes in northern Wisconsin are beginning to "turn over". This is a function of the surface waters cooling with the season. As the surface water cools it becomes more dense and begins to sink, thereby forcing the warmer water beneath to rise. The result is a mixing of the water and which brings some of the nutrients in the lower levels to the surface, thereby affecting the availability of nutrients to algae. In some cases there is increased growth of algae at this time, and there is often a change in the feeding habits of fish.
Oct 13 There were a few snowflakes in Green Bay again today. The temperatures were a little warmer and the winds were stronger, out of the west--averaging 16.8 mph for the day with a peak of 39 mph.
Oct 12 Green Bay's low temperature was 27° F this morning. That is our lowest temperature since April 8. There was also a little snow (trace).
Oct 11

There were snow flurries widely in Wisconsin today, with a few areas in the north reporting at least an inch of accumulation (and more in western upper Michigan).. Green Bay's low temperature was 31° F as a large cold air mass moves in from central Canada.

Oct 10 Here's another increment of the photo series for leaf color change in Rhus hirta (staghorn sumac). Note that the intervals are not all equal. The peak of bright red color was between Sep20 and Oct 3 and the leaves fell very quickly thereafter.
Oct 09

Many of the Asters can still be found in flower in the northeastern Wisconsin area, including A. ciliolatus, A. cordifolius, A. ericoides, Aster laevis, A. lanceolatus, A. lateriflorus, A. macrophyllus, Aster novae-angliae, A. pilosus and A. sagittifolius. Common names and photos of these species can be found at this web site.

Euonymus alata (burning bush) leaves are bright red now on UW-Green Bay campus.

Oct 08 Today was unseasonably warm in northeastern Wisconsin, with the temperature reaching 77° F in Green Bay.
Oct 06

The temperature in Green Bay reached 35° F this morning and there was scattered frost and a very heavy dew.

This should be a good weekend for viewing the Fall leaf colors in northern Wisconsin.

Oct 04

Yesterday I posted a photo of leaf color change for Rhus hirta over the last 6 weeks. Last night Green Bay experienced thunderstorms with strong rains (1.25 inches) and strong wind. Here are two photos documenting the change of the same Rhus hirta clone since yesterday. It appears that there was a significant loss of leaves overnight.

Oct 03

Canada Geese in large numbers are grazing in fields in the Green Bay area. In evening and mornings there have been 400-500 geese in this field in Allouez in recent days. They are extremely vocal and goose music is among my favorites. If you try this web site you can scroll down to the microphone and click to hear the call of the canada goose.

Compare the leaf color of Rhus hirta (staghorn sumac) over the last 6 weeks.

Oct 01

Autumn leaf color is advancing quickly in northeastern Wisconsin. In some locations the leaves have begun to fall and in others there are still many green leaves. Here's a photo of Acer rubrum (red maple) in Marinette County. The fully green tree to the left is Quercus ellipsoidalis (Hill's oak ). For help in identifying red maple click here.

© 2001-2004 The Cofrin Center for Biodiversity and the University of Wisconsin Green Bay, All Rights Reserved
Last updated on May 20, 2015