Meteorological winter versus astronomical winter

AccuWeather Melissa Constanzer explains the meteorological calendar, how it helps keeping records and why the seasons change.

Transcript

00:00As we head throughout the next couple of days,

00:02we know that winter is really getting pretty close.

00:05Less than three weeks away, the first day of winter,

00:07which is December 21st, that is the winter solstice.

00:11We are actually already in winter.

00:13It's just meteorological winter.

00:15If you look at the meteorological calendar,

00:17we break it up into three months for each season.

00:21And there's a reason why we do all this.

00:24First off, we base it on temperature

00:26and when those months tend to fall.

00:28Then, of course, we do those three-month increments,

00:30all to help keep track of records.

00:32If you're familiar with the solstice,

00:34it happens on different days.

00:36It can be a kind of a range of days,

00:38depending on how it is and the start of each season.

00:41So that's not really great for us trying to keep records

00:44of what is the warmest fall on record

00:46or the coldest winter on record.

00:48So this is why we have meteorological winter,

00:51which we are officially in as of yesterday.

00:53But the winter solstice, that doesn't happen

00:55until December 21st, 4.19 a.m. Eastern Time.

00:59And that is, again, the start of astronomical winter.

01:02Also, the shortest day of the year.

01:05After that, yes, you can say at least it's getting brighter

01:08each and every day as we head towards the end of June.

01:11But, of course, it's all part of why the Earth

01:15is tilted on the axis here.

01:16And that tilt is what ultimately gives us the season.

01:20So as the Earth moves around the sun,

01:23you can see it's that tilt that is away

01:26or towards the Earth, depending on which season it is,

01:29that helps create kind of the differences there

01:31in the weather patterns, not only,

01:33but also, of course, the difference in daylight, too,

01:35that we get.

01:36So for winter, the tilt of the axis is away from the sun.

01:39For the Northern Hemisphere,

01:41it means the nights are longer right around the solstice.