The first use for an aerosol package arose during World War II, but the idea of using low-pressure liquefied gas to atomize droplets of liquid in the air was developed in 1924. Canisters filled with insecticide and propellants were used to protect U.S. servicemen from insects carrying diseases such as malaria.
Best Time for Good Weather and Swimming: The warmest weather in Santorini (and all the Greek islands) is between June and September when itâs sunny, hot, and the water is perfect for swimming. Water temperature heats throughout the summer months and is warmest in August and early September.
The average temperature in Helsinki in September is quite mild at 11.5 Â°C (52.7 Â°F). Afternoons can be mild with average high temperatures reaching 15 Â°C (59 Â°F). Overnight temperatures are generally a little cool with an average low of 8 Â°C (46.4 Â°F). In September the range/ variation of daily mean temperatures is 7 Â°C (12.6 Â°F). The weather in September is somewhat dry with rain once in a while. Just 71mm (2.8in) of H2O descends during on average 15 days.