The phrase "although fairly" is correct and usable in written English.
It can be used to introduce a contrast or concession, often indicating that something is true to a certain extent but not entirely.
Example: "Although fairly simple, the task required a lot of attention to detail."
Alternatives: "even though somewhat" or "despite being relatively".
Although fairly well developed, this sector lags behind that of other Scandinavian countries.
Although fairly niche in the UK, Pinterest is a major driver of retail referral traffic in the US.
Although fairly modern – he died only 45 years ago – this is the first of many examples of outstanding statues I encounter.
Although fairly small-scale, the vacation home exchange site has detailed information and the added advantage that potential home-swap partners can be contacted directly, allowing each party to ask as many questions as necessary to determine if the swap will work for them.
Although fairly eclectic, the overarching theme here is kindness, whether it be on the bucolic Feathers Are Falling or The Very, Very Best, a song that could only be written by the wizened hand of a man who's lived through the harrowing and heartwarming.
Either the batter was much too liquid and ran out from under the hoops, or it was too stiff, and although fairly easily cooked on the griddle the resulting crumpets didn't have the characteristic "honeycomby, labyrinthe" structure – they were what bakers call "blind".
Although a fairly obscure virus called Zika has become a global health emergency.
Internet access, although still fairly limited, has also increased in the early 21st century, including the installation of fibre-optic cables.
The Oncoscore developed in this study, although performing fairly in the studied population remains to be validated in an external population of solid cancer patients requiring ICU admission.
That is indeed a lot of extra testing, which exposes many women to more radiation, a potentially painful (although usually fairly simple) biopsy procedure and financial costs.
Although a fairly strong low-level circulation developed, there was insufficient warming of the center to produce a significant drop in barometric pressure at the surface.
