Rain, no rain
Source: Linnanmaa weather station .
Winter, spring, summer, fall
Winter in Oulu, Finland, in months 11–12 and 1–3, spring 4-5, summer 6–8, fall 9–10.
No, morning, afternoon
Morning: weekdays at 7–8; afternoon: Monday–Thursday 16–17, Friday 15–16.
Sun above horizon, according to the R package suncalc .
Event, no event
Occurrence of an ice hockey game (source: ).