On March 20 you may notice the spring equinox (also known as the 'vernal equinox') on your calendar marking the first official day of spring.

Natalie Hasell, Warning Preparedness Meteorologist with Environment & Climate Change Canada says spring equinox is "the time when the number of hours during daylight equals the number of hours during the nighttime for that 24-hour period."

It usually falls towards the latter end of March like the 20 or 21, depending on the year.

"If you're looking at what's going on on the planet, it's that time when the plane of the earth's equator passes through the centre of the sun. So as the planet goes around the sun we'll see this happen twice a year, once on the vernal equinox and the other during the autumnal, or the fall equinox," says Hasell.

These are also known as the 'first day of spring/fall,' but she says that you should not expect the outdoors to suddenly be green and warm.

"The calendar, or the astronomical spring, does not necessarily mean that we have spring-like conditions on the ground everywhere, and certainly here, where Southern Manitoba has seen snow well into May . . . In terms of the weather we see here, there's actually very little relationship."

Hasell describes this as a lag between the different seasons where some days can be warmer, but overall conditions will warm up slower than the calendar may make us believe. Although uncommon, she does note that there have been occasions where spring conditions actually happen as expected in late March and April.

"For the week of the 16 of March to the 23 of March - so that would include the equinox time - most of Manitoba should see a warm-up," but she reminds people to still be prepared for unexpected snowfall that can cause dangerous road conditions like Thursday morning (March 16).