Are there any secular historical references to the natural phenomena that occurred at the crucifixion and resurrection? The Scriptures record that there was three hours of darkness during the crucifixion of Jesus.  This is a pretty significant meteorological event.  Furthermore, the morning of Jesus' resurrection, the Scriptures indicate that there was an earthquake.  Additionally, when Jesus died, the curtain of the Temple was apparently torn in two.

Now from the sixth hour there was darkness over all the land until the ninth hour.  Matthew 27:45 ESV
And behold, the curtain of the temple was torn in two, from top to bottom. And the earth shook, and the rocks were split.  Matthew 27:51 ESV

I don't know if there are historical records of any earthquakes, eclipses, or such things in any of antiquity.  Yet, I am indeed curious to know if there are, and, if so, if there are any secular historical records that could match up to these events that surrounded the death of resurrection of Christ.
Julius Africanus was an early third century Christian historian.  He says that a pagan historian named Thallus mentions the darkness that occurred during Jesus' crucifixion, and that Thallus explained it as an eclipse.  However, Africanus correctly notes that an eclipse is not possible during the Jewish Passover when Jesus was crucified (see: On the Circumstances Connected with Our Saviour’s Passion and His Life-Giving Resurrection).

Africanus also mentions another historian named Phlegon who wrote about the darkness and earthquake.  James Ussher, in his Annals of the World (first published in 1658), writes: "“Phlegon stated that in the 19th year of Tiberius (as Eustathius Antiochus noted in Hexaemeron) and the fourth year of the 202nd Olympiad (that is 33 AD), the following events took place... 'There was the largest and most famous eclipse that had ever occurred. The day was so turned into night at the sixth hour (noon), that the stars were seen.  Also, an earthquake in Bithynia destroyed many houses in the city of Nicaea’” (Annals of the World 6503).

In addition, Pliny the Elder, a first century Roman historian and naturalist, wrote that "“[t]he largest earthquake happened in the principate of Tiberius Caesar when twelve cities in Asia Minor were razed to the ground in one night” (Pliny's Natural History 38).

So, while there are secular accounts of the darkness and earthquake, they are quoted and preserved by Christian writers (with the exception of Pliny's writings, which were preserved independently; yet, Pliny doesn't date the earthquake except to say it was during Tiberius' reign).