Windsor, Ontario

Alder season occurs from late February to mid-June. The counts fluctuate mostly from low to moderate. Occasionally high counts occur during the early season. The alder season is highly affected by weather. They can be significant in causing allergic reactions.

Ash pollen season can last approximately up to six weeks and can start from the end of March to late April and end mid-May to early June. The counts range from low to high throughout the season and they are considered to be allergenic in highly sensitized individuals.

Beech produce moderate counts and other years hardly any pollen is observed. The season varies a great deal from year to year due to the effect of weather and possible cycles for this species. The season can start from mid-April to mid-May and end mid to late May. May cause allergic reactions in individuals who are highly sensitized.

Birch season can begin from the first to third week of April and end around mid-May to early June. Generally the counts are low and moderate. Rare high counts can occur. The timing of the season can vary from year to year as well as the amount of pollen produced. They are considered important allergens.

 Cedars, junipers and yews can produce low to high counts from about mid-February to early June. The season is very sporadic due to the number of species present and the effect of weather.

Chestnut are important allergens and the season lasts approximately four weeks. The season can start from the second to the fourth week of May and end mid-June to early July. The Horse Chestnut, which is the most allergenic, is only found in low numbers.

Elm season can last about four to five weeks with an early season that occurs late February to early March with low and the occasional moderate counts possible. The main season can begin from mid-March to early April and end mid to late April. The types of seasons that occur every year is partially dependent on weather. The counts can get high with mostly low and moderate counts observed through the season. The elms are important allergens in individuals who are sensitized.

Grasses produce moderate to high counts from mid-May to mid-July. The season starts from mid to late April and ends around mid-October, depending on the season. There is another peak with moderate counts early September. This species is unique to certain sites (Montreal being another location). The grass season starts late April and lasts until late October.

Hickory have a short early season towads the end of April. The main season can last almost a month. The season can start early May to late May and end early to late June. Some moderate counts can be observed in the main season.

Maple trees have more than one season because of the number of species present at this site. The first season, which lasts approximately one and a half weeks, can occur from mid-February to early March with generally only low counts observed. This season may not occur or may be missed due to how early it occurs. The main season can start mid to late March and ends early to late May or early June. Significant counts can be observed ranging from low to high. The seasons vary from year to year not only for the timing but for the amount of pollen produced. Some species are known to cause allergic reactions.

Mulberry season can last from four to five weeks. The season can start from mid-April to mid-May and end late May to mid-June. There are many species found at this site and the counts can be very high. They can cause allergic reactions in individuals who are highly sensitized.

Nettles and parietaria occur in significant numbers that may cause allergic reactions and are important, especially due to their small size. The season usually starts from the second week of May to late May and ends late September.

Oak season, in warm years like 2012, can start late March. Generally the season starts early early to late April and end from mid-May to mid-June. The seasons can vary a great deal from year to year which is mostly attributable to weather conditions. The counts can reach very high levels and certain species are highly allergenic.

Season fluctuates a great deal for Pine, fir and spruce due to the effect of weather and the number of species present. The season can start from late March to late April and end early to mid-June. High counts are observed and can be of significance to those individuals who suffer from allergies to this group.

Plantain are important allergens. Moderate and high counts occur at this location. The season can start late May to mid-June and end late September. They are considered important allergens even at low levels.

Poplar and aspen season is very dependent on weather conditions. An early season can occur late February to early March, if the weather conditions are favourable. The main season can start from early March to early April and end early to late May. The timing of the season as well as the amount of pollen produced is highly affected by weather. The counts can reach the high range and may cause allergic reactions.

Low counts of ragweed pollen occurs mid-July to well into October. Low counts can be observed early July. The season is mostly from mid-July to well into October. Moderate and high counts can occur from August to mid-October.

 Walnut season lasts approximately a month. The season can occur from early May to mid-May and end the firs to third week of June. The beginning of the season can be sporadic. Low and moderate counts are observed.

 Willows have a long season that lasts almost two months. The season starts from late March to mid-April and can end from mid-May to almost mid-June. The counts vary from low to moderate throughout the season. There are several species and they cause allergic reactions in individuals who are highly sensitized.