The phrase "a month when the" is correct and usable in written English.
It can be used to refer to a specific month in which a particular event or situation occurs.
Example: "April is a month when the flowers begin to bloom and the weather starts to warm up."
Alternatives: "a time of year when the" or "a period when the".
The variable cost for each active user was about 50 cents a month when the company started, but has been dropping along a curve to 9 cents a month.
Mathew Owens, who lives in Reading with his wife Jo Cordy and their two children, says he cancelled his sole-named HSBC Advance account, which cost £12.95 a month, when the bank decided to change its mind over who the roadside assistance would cover.
He was paying $450 a month when the neighborhood's median rent was about $1,200.
As if to underscore the problems, the national statistics authority reported on Thursday that unemployment had jumped to a record high 18.4 percent in August, a month when the tourist season normally lowers the rate, from 16.5 percent in July.
The city's restaurants and catering operations shed about 2,000 jobs in December, a month when the hospitality industry usually adds to its payroll.
BAMNOD, India — The 50-year-old farmer knew from experience that his onion crop was doomed when torrential rains pounded his fields throughout September, a month when the Indian monsoon normally peters out.
The M100, Marketocracy's best 100 investors, have been holding Curagen since February, a month when the stock lost about one-fourth of its value after dropping from a high of $9.53 in January.
On 7 February it was announced Jacob Murphy would be joining Swindon Town for a month when the loan window opens (8 February).
Well continued their good form, with McCall winning the award again in October, alongside player of the month Keith Lasley, in a month when the side went unbeaten.
"This is a month when the tourism industry starts to hit its stride," he said.
Who'd pay $800 plus $13 a month when the cable company's DVR costs $5 a month?
