Spiders and Robins can predict the weather in Irish folk Tradition
The spider is one of folk trads great short term weathermen. If you get up in the morning and see the spider has made a short web its going to be wet and windy, if hes made a big web its going to be a good day out.
The Robin is one of the most favoured birds in Irish folk tradition, maybe because red is the colour of the otherworld for us. The robins also a great way to tell the weather. If they are down in the bushes its going to rain if they are up in the air its going to be good.
Weather prediction might not seem important to us today but in a preindustrial economy tied to harvesting crops it was very important to know when to harvest or when to bring in the hay. You cant save wet crops for fodder.