In spring, the natural world revives after winter as temperatures gradually rise

. The Earth's axis begins to tilt towards the sun, resulting in longer and warmer days

. Natural Events:

• Plant Growth Dormant plants begin to grow again, and new seedlings sprout

. Many flowering plants bloom in succession, sometimes when snow is still present

. Trees start to bud with new green leaves

• Hibernating Animals Animals that hibernate, such as bears, awaken and become active

• Migratory Birds Many birds migrate poleward in response to warmer temperatures

. Migrant birds return to areas such as the UK

• Frogspawn Frogspawn (amphibian eggs) starts to appear in ponds

• Weather Snow begins to melt, increasing stream runoff, and frosts become less severe

. Unstable weather may occur when warm air from lower latitudes meets cold air from the Polar regions

Other Facts about Spring:

• The Northern Hemisphere generally defines spring as the time between the vernal equinox (around March 20 or 21) and the summer solstice (June 21 or 22)

. In the Southern Hemisphere, it occurs from September 22 or 23 to December 22 or 23

• Spring is associated with the sowing of crops in European cultures

• Observed "season creep" indicates that spring's phenological signs are occurring earlier in many regions, about two days per decade

• Common holidays that occur during the spring include Easter, Passover, April Fools' Day, Earth Day, Mother's Day, and Father's Day