1841 - He lived at Tyn Llwyn (Trefdraeth) with his son, Evan, and mother, Elizabeth.
Assuming this is the correct family (are you descended from Evan?) Evan's baptism was at Trefdraeth 22 Jun 1834 - Evan Griffith son of Thomas & Elizabeth Evans, Tyddyn llwyn, farmer.
Also at Trefdraeth there was a marriage between Thomas Evans (bachelor) and Elizabeth Jones, both of Trefdraeth, on 25 Sep 1833. Both signed, the witnesses were John Parry and Margaret Williams.
Elizabeth Evans of Ty'n llwyn was buried at Trefdraeth on 4 Feb 1839, age 25.
Thomas & Elizabeth had two other sons baptised at Trefdraeth:
Emmanuel son of Thomas & Elizabeth Evans, Ty'n llwyn, farmer - 13 Nov 1836
Thomas son of Thomas & Elizabeth Evans, Ty'n llwyn, farmer - 10 Feb 1839
Both died young and were buried at Trefdraeth:
Emmanuel Evans, Ty'n Llwyn age 2 on 13 Mar 1838
Thomas Evans, Ty'n Llwyn age 3 on 3 Nov 1841
But there is a problem!
Thomas Evans' mother Elizabeth died in 1842 and was buried at Trefdraeth. The burial register has Elizabeth Jones, Ty'n llwyn, age 79, 2 Jul 1842 (Jones was Elizabeth's maiden name retained under the old Welsh patronymic system).
Elizabeth's death registration has:
Elizabeth Evans, age 79, died 28 Jun 1842, Trefdraeth. She was described as the widow of
Emanuel Evans, the informant was Robert Evans.
Emmanuel Evans was also buried at Trefdraeth - 31 Aug 1836, age 73, again the abode was Ty'n Llwyn.
So who was Thomas Evans father? The 1851 marriage to Ellen Williams gives his father as Evan Thomas, which agrees with the baptism at Newborough in 1802. The information above suggests Emanuel Evans.