Here’s How Frost-Free Season Affects Allergy Season

Pollen allergies are not just a nuisance. Asthma symptoms can be triggered by exposure to pollen, with the number of emergency room visits increasing on days with high pollen. An analysis of emergency room visits in New York City during 1999 showed peaks in the number of visits correlated with high spring pollen counts, and is consistent with other

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Western Snowpack Trends

April 1 marks the close of the winter precipitation season in the West, a good time to take stock of the snowpack in the mountains. The snow measurement indicates how much meltwater from that snowpack will be available for residential, agricultural, and commercial use during the dry summer months that follow. Even with the heavier snow in parts of

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Growing Season Growth: Additional Frost Free Days

​As the climate warms from the increase of greenhouse gases into the atmosphere, the last spring freeze is trending earlier and the first fall freeze is coming later. This means the growing season is getting longer, and so is the pollen season— whether it is from tree pollens in the spring, grass pollens in the summer, or ragweed in the fall. A

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Cherry Blossoms in a Changing Climate

The blooming of the cherry blossoms along the Tidal Basin of Washington, D.C. is an annual rite of spring. During the period from 1981-2010, the average peak bloom date was April 1. This year, the National Park Service forecasts the blossoms to peak slightly earlier than average, between March 27-31. The warm February was the reason that both the

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change in days with heavy precip

Heavy Rainfall Trends Across the U.S.

With flooding in parts of the Mississippi Valley and a strong Pacific storm coming into the Northwest, we examined the trend in the number of days each year with heavy precipitation at 244 individual sites in the U.S. This expands our nationwide-averaged heavy precipitation analysis from earlier this year, complementing the 2017 Climate Science

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allergy season and climate change

Here’s How Frost-Free Season Affects Allergy Season

Pollen allergies are not just a nuisance. Asthma symptoms can be triggered by exposure to pollen, with the number of emergency room visits increasing on days with high pollen. An analysis of emergency room visits in New York City during 1999 showed peaks in the number of visits correlated with high spring pollen counts, and is consistent with other

more
Longer frost-free seasons mean longer allergy seasons

Growing Season Growth: Additional Frost Free Days

​As the climate warms from the increase of greenhouse gases into the atmosphere, the last spring freeze is trending earlier and the first fall freeze is coming later. This means the growing season is getting longer, and so is the pollen season— whether it is from tree pollens in the spring, grass pollens in the summer, or ragweed in the fall. A

more
western snowpack trends

Western Snowpack Trends

April 1 marks the close of the winter precipitation season in the West, a good time to take stock of the snowpack in the mountains. The snow measurement indicates how much meltwater from that snowpack will be available for residential, agricultural, and commercial use during the dry summer months that follow. Even with the heavier snow in parts of

more
more snow, less snow

These U.S. Cities Are Getting More (and Less) Snow

There were some unusual highs and lows to snowfall totals across the U.S. this winter. Take a look at the long-term trends in total snow for more than 1,100 sites.

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cherry blossoms in a changing climate

Cherry Blossoms in a Changing Climate

The blooming of the cherry blossoms along the Tidal Basin of Washington, D.C. is an annual rite of spring. During the period from 1981-2010, the average peak bloom date was April 1. This year, the National Park Service forecasts the blossoms to peak slightly earlier than average, between March 27-31. The warm February was the reason that both the

more
cherry blossom projections

Projected Cherry Blossom Bloom Dates in a Warming World

While the climate continues to warm from the increase in greenhouse gases, the average date of the peak blooms will move even earlier in the year. One study, referenced by the NPS, was successfully used to forecast peak bloom dates retroactively from 1991-2010.

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spring warming

Warming Spring

March 1 signals the beginning of meteorological spring. In spite of the wintry precipitation that has kicked off the month in parts of the country, springs across the U.S. are getting warmer with climate change. On average, spring has warmed a little more than 2°F in the U.S. since 1970. The strongest warming, as examined by the NCEI climate

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increasing rainfall extremes

More Downpours: Increase in Heaviest Precip Events

Rivers continue to swell in the Ohio and Mississippi Valleys. More than 10 inches of rain fell last week in Arkansas and Louisiana. While the individual weather pattern may allow for heavy rain, the heaviest of this precipitation is increasing as the world warms from climate change.

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mild winters disturb chill time

Fruit Trees Need Winter Chill for Spring Growth

Apples, cherries, and peaches grown in the U.S. are worth more than $4 billion dollars annually. The trees that produce these and other fruits are increasingly at risk as winters warm from climate change. Fruit trees and certain bushes must go through a dormant period each winter in preparation for producing fruit the following spring and summer.

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extreme cold

The Future of Extreme Cold in a Warming World

For much of the U.S. east of the Rockies, middle to late January tends to be the coldest time of the year. Even though extreme cold can still happen in winter, as was seen earlier this year in much of the country, the frequency and intensity of extreme cold is declining as the world warms from the increase in greenhouse gases. Digging deeper, this

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global temp review

The 10 Hottest Global Years on Record

According to NOAA, 2017 finished as the third-warmest year globally since records began (NASA ranked it second-warmest). This is the warmest year on record without an El Niño in the Pacific Ocean, as neutral conditions existed in the Pacific until La Niña developed in the fall. Even so, the global ocean was still the third warmest on record, highl

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