July in California it is hot. So when I tell you that the greatest danger
for rice is from cold temperatures you may scratch your head. California
rice is grown primarily north of Sacramento. During the night temperatures
can drop below 60° if the weather is right.
When the temperature drops below 60° a portion of the pollen structure deep down in the plant begins to die. If the temperature gets down to 55° essentially all the pollen dies. This is why growers watch the weather carefully, because the plant shows no external symptoms. They will not know that the pollen has died until there is reduced or no grain at harvest.
To help with this situation, the rice industry maintains a system of weather stations that growers may access. Growers also may raise the water level in their fields to help protect the fragile pollen structure.
One of the easily observed birds that hunt in the rice fields all summer is the Great Egret, Ardea alba. It is a very large bird with a wing span over four feet that hunts crayfish and other fish in the rice fields. Because of their size and their method of hunting by stealth, they move with a slow, distinguished grace that is delightful to watch. Somewhat more difficult to find (and very shy around cameras) is the Great Blue Heron, Ardea herodias, that has a wingspan of six feet.