The phrase "are most favourable" is correct and usable in written English.
It can be used when discussing conditions, situations, or opinions that are particularly advantageous or beneficial.
Example: "The current market conditions are most favourable for investment opportunities."
Alternatives: "are highly advantageous" or "are very beneficial."
Excessive focus on the deficit will force the political debate on to terms that are most favourable to the Tories.
The government and Isis are both strong enough to gain successes where conditions are most favourable to them.
Growing season, also called Frost-free Season, period of the year during which growing conditions for indigenous vegetation and cultivated crops are most favourable.
City tax accountants have warned that from next April, when the tax changes take effect, Britain will drop down the G20 league table of countries where tax rates for senior executives are most favourable.
Generally, the areas deeper than hydrocarbon expulsion threshold (3200 4300 m of depth or 0.8%1.3%% of Ro) are most favourable for shale oil accumulation, which matches the actual oil production data.
The prospects for commercial application of OTEC technology seem bright, particularly on islands and in developing countries in the tropical regions where conditions are most favourable for OTEC plant operation.
The results indicated that participants were most favourable to offshore development and least favourable to development at the identified sites.
In the delta plain, the relatively high and dry alluvial ridges of abandoned or active rivers were most favourable for habitation.
Under the reported experimental conditions, a duration of 48 h for aging has been most favourable, after which there appears a negative effect.
When to go? Spring is the best time to visit, when the weather is most favourable for exploring by foot, but there's always a wide range of events going on.
