Most likely. Browning of the leaf edges is what they do when stressed by high temperatures and lack of soil moisture. Especially this time of the year. I have the drip irrigation set to go twice a week but it does not reach all of the surface roots well so once I week I manually water and that lasts at least a week. Something you have to do when the temps are regularly in the 100s and there is no rain.

Try also making sure that they have 3-4" of organic mulch (if they have less than that or no mulch). Spread it outwards towards the drip line or a little further than that if the location is windy.

The leaf edges are fine, only the flowers have browned mostly at the bases. I think they are being replaced with Little Limes.