Retailers continue to face a difficult few months as the outlook is mixed, according to two research studies from KPMG and BDO.

The monthly BRC-KPMG Retail Sales Monitor found that like-for-like sales in January achieved the highest increase seen since December 2011.

David McCorquodale, head of retail, KPMG, said: 'Many retailers will be pleased with their sales campaigns as of 2013 roared into life producing double-digit sales increases in several categories in the first week. Sadly a blanket of snow mid-month slowed the charge as payday approached.'

BDO's survey confirms that January was a month of two halves. The firm's latest High Street Sales Tracker show the first week of the year recording like-for-like growth of 14.3% - the best weekly performance in three years. However, overall like-for-like sales in January dipped 0.4% year-on-year.

BDO says retailers were also hit by the heavy snowfall in the third week of January, which put already cautious shoppers off visiting the high streets and shopping centres. This together with the trend towards 'desk shopping' or through mobile devices, also explains the rise in non- store activity which was up 41.5%.

Don Williams, BDO national head of retail and wholesale said: 'After a reasonable December and a strong start to January, retailers are likely to be disappointed the month wasn't slightly more positive. With February a notoriously difficulty month for the sector, retailers will need to continue to negotiate the difficult consumer environment.'