Flights to Rwanda are promised by ‘spring’—but when is spring?

Speaking about the government’s Safety of Rwanda Bill on Sky News this morning, Chief Secretary to the Treasury Laura Trott MP said: “We will be ready for flights to take off in the spring, when the legislation passes.”

Asked what this meant in terms of dates, Ms Trott replied: “Well there’s lots of definitions of spring, but we’re hoping to get them up and running as quickly as possible.”

According to the Met Office there are two definitions of spring: astronomical and meteorological. The first refers to the position of earth’s orbit in relation to the sun. This year astronomical spring runs from Wednesday 20 March to Thursday 20 June.

Meteorological seasons are set according to the calendar, and each lasts three months. By this measure, spring always begins on 1 March and ends on 31 May. 

In order to fit with one of these definitions of spring, therefore, Rwanda flights would have to take off no later than 20 June. 

Meanwhile the website of the Royal Observatory in Greenwich says the start of spring can also be calculated using phenology—the study of seasonal changes in plants and animals.

It states: “In reality there are no hard and fast criteria to determine the start of each season; the onset of spring, for instance, could be the date on which the first daffodil flowers or the first birds make their nests. The dates of these are not only extremely difficult to determine but also vary quite dramatically through the United Kingdom, let alone the rest of the world.”

A spokesperson for the Home Office declined to comment on the timing of spring but said: “We have robust operational plans in place to get flights off the ground to Rwanda.”