Finished winter, place in the spring! The Vernal equinox on Thursday, March 20, marked the start of the “love season”. Will the good weather be there? Here are the main weather trends in April, May and June.
This Thursday, March 20 at 10 a.m. and 30 seconds precisely, the spring equinox occurred in our hemisphere, marking the end of winter and the beginning of spring. More precisely, it is the moment of the year when the sun crosses the equatorial plane of the earth. At this moment, the star is at the Zenith of the Ecuador. Consequence? The nights and the days have the same approximate duration all over earth. Spring settles until summer solstice on June 21.
The season of the first buds, the first rays of sun and the first sunburn, therefore started this Thursday, March 20, 2025. Does this spring equinox mark the arrival of sunny days and the end of the greyness? We take stock of the main meteorological trends that await us this spring.
What weather after the spring equinox? Good news announced
According to specialists in Météo Francethis season should be marked by “more frequent high pressure conditions than normal in France”. If more important disruptions than normal are expected in the most northern regions of Europe, “A softer scenario than normal is very likely for France“” from the point of view of temperatureswith “colder occasional episodes” possible. Spring will be hot! We take stock of the three months of the coming spring:
In April 2025, the weather channel announced “a dry and gentle month” overall, with some late frosts due to clear nights and the extreme south of France on the border with Spain, near the Pyrenees, marked by a few rains. In May 2025, we should expect a degradation of the weather, “a priori rather to the south” with frequent showers and a return of freshness and humidity throughout the country. Finally, in June, the most likely scenario is the return of heat “with temperatures from +1 ° to +1.5 ° C above medium-sized”, with thunderstorms from the Southwest. To summarize this spring, the most likely scenario tends to warmer temperatures than seasonal normal.
How is the date of spring set?
From an astronomical point of view, spring begins at the time of the Vernal equinox, which can take place between March 19 and 21. It lasts until summer solstice. This means that spring lasts about three months. The date of the equinox is calculated for each year by astronomers and mathematicians. It is a question of providing the exact moment when the plan of the equator and that of the trajectory of the earth coincide. A calculation made necessary by the discrepancy between our calendar, our hourly system and the movements of the stars. First, the orbit of the earth is not perfectly circular, which depend on its position on this orbit, the earth can be more or less close to the sun (between 147 million kilometers minimum and 152 million kilometers maximum). This inevitably makes the durations of each season very irregular and therefore the Variable spring date.
Other explanation: The earth does not take exactly 365 days to go around the sun. In this our Gregorian calendar, established in the 16th century, is far too simplistic. It takes 365.2422 days very exactly (365 days, 5 hours and 46 minutes) so that we have done the full tower of the star! We are therefore forced to add from time to time on February 29 (during bissextile years) to correctly correct (and partly only) this discrepancy. A punctual addition which artificially repels the date of spring of one day during the bissextile years. This explains why astronomers “advanced” on March 20 last year. And that the situation presents itself again this year.
During the establishment of the Julien calendar by César, in 45 BCE, the spring equinox had been set for March 25, according to the imprecise observations of the time. But the absence of February 29 in this ancient calendar ended up moving this date until March 11 in the 16th century … It was only during the establishment of the Gregorian calendar (the one we use today), in 1582, that an approaching date of March 21 was chosen.
The date of “common” spring should not be confused with that of meteorological springwhich begins every year on March 1, allowing meteorologists to do their seasonal calculations on a whole month. In meteorology, we consider that spring begins on March 1 to end on May 31: in this discipline, we characterize spring as a period of warming temperatures (under our latitudes) and increased duration of the day. It is also one of the most difficult seasons to analyze in this discipline. However, it is the equinox that continues to mark the advent of spring in the minds of people.
What is the definition of the spring equinox?
The word equinox comes from the Latin “æquinoctium” (“equal night”) Because the most visible phenomenon for humans is that the duration of the day becomes identical to that of the night. The reason for this phenomenon? The equinox corresponds to the time of the year when the sun crosses the equatorial plane of the earth. The star is then at the Zenith of Ecuador, which allows day and night to share time in equal parts. And this in the two hemispheres, south and north. On our side, the days extend and we are halfway between the short days in December and the long days in June. During the equinox, the axis of rotation of the earth on itself and the axis of rotation of the earth around the sun therefore correspond exactly. On our planet, during the equinox, our star appears to the east to the dawn to disappear battery to the west.
This phenomenon is also linked to geometry. The axis of rotation of the earth is naturally inclined by 23.4 ° compared to the plan of its orbit. In other words, Our planet “leans” in relation to the plan on which it revolves around the sun (see diagram below). The star therefore lights it up differently depending on the moments of the year. This phenomenon explains why the days extend or shorten between summer andwinter. This also gives birth to the seasons, due to the warming or cooling of the air masses and the oceans according to the time spent every day under the shelves of the star. The distance between the sun and the earth, on the other hand, has no direct link with the temperature. Know for example that the earth reaches the point closest to the sun (the perihelion) on January 3, that is to say in the heart of our winter.
Spring equinox: what does the image phenomenon look like?
The equinox takes place twice a year: between March 19 and March 21 (spring or vernal equinox) and between September 22 and 23 (autumn equinox). In the spring the duration of sunshine increases at the equinox to reach 4 p.m. at the end of June, during the summer solstice. Conversely, the autumn equinox begins a period of reduction of the day which descends barely more than 8 hours at winter solsticearound December 21. During the equinox on the other hand, no jealous: day and night are supposed to last 12 hours each. These data nevertheless vary slightly since the shape of the earth is not perfectly regular and the atmosphere slightly diverts the rays from the sun. Thus, in Paris, on March 20, last year the sun rose at 6:52 am to go to bed at 7:03 pm. The duration of the day was therefore very slightly greater than 12 hours. It is also at the time of equinoxes that the duration of the day increases/decreases the fastest in our latitudes.