Here's a graphic of how (most) Ninjago seasons pan to their respective seasons.

*Note: This assumes that Day of the Departed is celebrated in Autumn, as Halloween and Día De Los Muertos, DotD's 2 major inspirations, are both celebrated in Autumn.

#ninjago

Canon Age Ranges as of Dragons Rising Season 3:

Lloyd (Mental Age): 18-27
Predicted: 22-23
Lloyd (Physical Age): 20-30
Predicted: 23-26
Kai/Cole/Jay: 23-34
Predicted: 25-29
Zane: 106-113
Predicted: 109-111
Nya: 21-32
Predicted: 23-27
Pixal: 9-18
Predicted: 12-13
#ninjago