JCrand.. J. You will find San Diego great for cycling. Bike paths and lanes are decent, depending upon where you live. There are lots of cyclists here, so traffice should be gettting used to us.
As to weather- best in U.S. If on coast winter averages about 60's and summer lo 70's. (Averages...) If considerable inland can be much hotter in the summer.. Think about California it is consistant. ( ie-Jokes about how boring weaher anchor jobs are in Los Angeles..)Humidity low and pollen no problems. Compared to Los Angeles our air is pretty clean.
Sure you can find details on weather bureau/ newspaper web sites. Only negative factor is it is getting more crowded here everyday and it is expensive.