As if enough hasn’t happened this summer, it appears that the ragweed pollen season, which traditionally ratchets up the torment about now, is off to a precocious start.

Those homely but tenacious plants that can somehow muscle their way through sidewalks and outwit the densest blacktop began air-mailing their reproductive pollen grains as early as late July, said Marc Goldstein of the Asthma Center medical practice, which supplies The Inquirer’s daily pollen counts.

“We’re already starting to see some low-level ragweed,” he said.

Pollen forecasting is more challenging than predicting the weather, said Estelle Levetin, an allergy expert and professor emeritus at the University of Tulsa. Along with daily weather conditions, the total volume of pollen that will fill the air in a given season can vary tremendously.

But near-normal spring rains could favor a bumper crop around here this year, Goldstein said.

While the recent deluges have probably suppressed daily counts, rains aren’t weed-killers, as anyone with a lawn is well aware. Pollen levels this week, as measured by an automated sensor, remained “low.”

Once the cloudbursts back off, assuming they do someday, the counts are almost sure to climb.

“These are weeds,” Goldstein said. “They are really hearty.” They also are ubiquitous across the country and come in 50 different species, and one plant can produce a billion pollen grains in a season, he said.

And they are the bringers of “hay fever,” one of the great misnomers in the medical lexicon.

What is hay fever?

It has nothing to do with hay or fever, nor, thankfully, the coronavirus. The classic symptoms are runny nose, congestion, and increased asthma discomfort, according to the American Academy of Allergy, Asthma, and Immunology, and no pollen-allergy sufferer is likely to argue with that list.

Ragweed pollen does not induce fever or body aches. Its symptoms generally affect the sufferer from the neck up, as opposed to the coronavirus, which targets the lungs.

The three most common symptoms of COVID-19 are cough, fever, and shortness of breath, although some have reported body aches, fatigue, gastrointestinal upset, sore throat, conjunctivitis, and loss of the sense of smell.

None of those is commonly associated with hay fever, although congestion can sabotage taste and smell.

As for the origin of the term, Levetin said it evidently traces its roots to English physicians who noted that the symptoms tended to occur during the “haying” season. “Fever” wasn’t associated with temperature per se, but was a generic term applying to any illness.

The misnomer has stuck with the tenacity of ragweed, a shortened form of “ragged weed,” which is appropriately named. No one would mistake it for a chrysanthemum.

It is the common name for plants in the genus Ambrosia, Levetin said. The primary cause of allergy symptoms is the low-lying tooth-leaved variety.

How long is the season?

Too long for sufferers, and some evidence says they are getting longer.

The onsets, peaks, and durations have varied, but coincidentally they track neatly with the hurricane seasons.

Pollen counts typically bump to the “moderate” to “high” levels in mid- to late-August, and “extreme” levels in mid-September, based on historical data.

On rainy days, counts would be low as pollen is washed out of the atmosphere. The ideal conditions for pollen flight are dry days with decent breeze, say, 10 to 15 mph.

Darkness tends to kill the mood, and counts go down after the sun sets, although some people might sneeze more at night because pollen can stick to clothing.

By late September, the season usually shuts down around here, although the seasons appear to be expanding, the result of increasing temperatures and carbon dioxide levels.

“The season is starting earlier, ending a little later,” said Goldstein.

Pollen volume might well be increasing, said Daniel Katz of the Dell Medical School at the University of Texas at Austin. His expectation is that “pollen suffering is going to get worse” in the future.

Ambrosia, the ragweed genus, said Goldstein, comes from “a Greek term that means ‘immortality.'

“So I think we’re going to be living with it for a long time.”

Staff writer Stacey Burling contributed to this article.