$\text{The temperature was cooler than } 80^{\circ} \text{F and it was not sunny.}$

$\text{The temperature was cooler than } 80^{\circ} \text{F or it was not sunny.}$

$\text{If the temperature was at least } 80^{\circ} \text{F, then it was sunny.}$

$\text{If the temperature was cooler than } 80^{\circ} \text{F, then it was sunny.}$

$\text{If the temperature was cooler than } 80^{\circ} \text{F, then it was not sunny.}$