From Longman Dictionary of Contemporary Englishseasonalsea‧son‧al /ˈsiːzənəl/ adjective [usually before noun]PERIOD OF TIMEhappening, expected, or needed during a particular seasonheavy seasonal rainsseasonal workers/employment etcseasonal jobs in the tourist industryExamples from the Corpusseasonal• The problem is that the number could be exceptionally hard to interpret because of seasonaladjustmentdifficulties.• This compares with 63 % at this time in 1997 and a five-year seasonalaverage of 53 %.• The seasonalcharts are for late evenings, with the Sun far enough below the horizon for the sky to be dark.• In Temperateregions there are regularseasonalcycles, ultimately driven by the regular cycling of the Earth around the sun.• Of the dailies, Today's circulation has registered the worstseasonaldrop, falling to 466,631 from 513,673.• wafflesserved with freshseasonal fruits• seasonalvariation in rainfalllevels• In other words, they have become instinctively aware of changes in daily and seasonal variations in temperature.seasonal workers/employment etc• The seasonal workers and outworkers do not receive the security or the minimalbenefits that are available to regular workers.• Men who had been seasonal workers formerly began talking of going stone-gathering and ditching during the winter.• For many seasonal workers, the biggest drawback can be the irregularhours and erraticschedules.From Longman Business Dictionaryseasonalsea‧son‧al /ˈsiːzənəl/ adjective1seasonal adjustment/ change/variation etcCOMMERCE adjustments you make or changes that happen because of the situation during a particular period of the year, that is not typical of the rest of the yearUnemployment figures were down during the summer months, even after seasonal adjustment.2seasonal business/employment/workers etcCOMMERCEHUMAN RESOURCES happening or needed only at a particular time of yearThousands of agricultural laborers arrive to do seasonal work on American farms. —seasonally adverbFrance’s seasonally adjusted foreign trade deficit