The best time to germinate your cannabis seeds outdoors will vary depending on the region you live in. Broadly speaking, you should do it when there's no risk of frosts, and winter has long ended. Having said this, we could give you some approximate dates depending on your region:

Northern hemisphere:

• Temperate climates with long summers: the temperatures are milder and, in general, the germination period goes from 1 April to 30 May, though the best moment is usually in early May.
• Colder and more humid climates with short summers: in these types of climates, germination can take place, in general, from 1 May to 30 June. The most recommended moment is usually early June.

Southern hemisphere:

• Temperate climates with long summers: the temperatures are milder and, in general, the germination period goes from 1 September to 30 October, though the best moment is usually in early October.
• Colder and more humid climates with short summers: in these types of climates, germination can take place, in general, from 1 November to 30 December. The most recommended moment is usually early December.

More info: When to germinate your seeds for outdoor growing