Different types of lawns/grasses, locations, topographical conditions and environmental factors cause grass to grow at quite different rates. This changes with both seasons and weather conditions.
As a guide the following may help:-
In the growing seasons/conditions, say during Spring and early Summer the average time between cuts is 3 weeks. In the drier months of the hot periods of Summer, this may require a frequency of 3 – 5 weeks. In the cold and wet months of Winter the average cut frequency may be 6 or even 7 weeks. However often in this cooler and wet periods different types of grass, collectively termed Winter grass may shoot through, thereby requiring a more frequent cut pattern.