Tacitus presents weather conditions and other phenomena with differing purposes. Here we will look at a a physical and neutral description of the weather in Britannia.
Caelum crēbrīs imbribus ac nebulīs foedum; asperitās frīgōrum abest. Diērum spatia ultrā nostrī orbis mēnsūram; nox clāra et extrēmā Britanniae parte brevis, ut fīnem atque initium lūcis exiguō discrīmine internōscās. Quod sī nūbēs nōn officiant, aspicī per noctem sōlis fulgōrem, nec occīdere et exurgere, sed trānsīre adfirmant. (Tacitus: Agricola)
The weather is foul, with dense cloud and rain; but severity of cold is unknown [literally: absent]. The days exceed in length those of our part of the world, the night is bright, and in the farthest part of Britain so short that you can scarcely tell the end of daylight from its beginning. So, they say, if no clouds intervene, the sun’s brightness is visible all night, not setting and rising but simply transiting.
asperitās, asperitātis [3/f]: severity; harshness
caelum, -ī [2/n]: weather; sky
clārus, -a, -um: clear
exsurgō, exsurgere [3]: rise up
foedus, -a, -um: foul
frīgor, frīgōris [3/n]: cold
fulgor, fulgōris [3/m]: [i] (here) brightness; gleam [ii] lightning
imber, imbris [3/m]: rain
lūx, lūcis [3/f]: light; daylight (and can also be used to refer to ‘dawn’)
nebula, -ae [1/f]: cloud
nox, noctis [3/f]: night; per noctem: all night / throughout the night
nūbēs, nūbis [3/f]: cloud
occidō, occidere [3]: go down; set (of the sun); note: not occīdō, occīdere [3] (with long /ī/) which means ‘kill’
sōl, -is [3/m]: sun
